diff --git a/src/BinLDrivers/BinLDrivers_DocumentRetrievalDriver.cxx b/src/BinLDrivers/BinLDrivers_DocumentRetrievalDriver.cxx
index 14728b3aa7..7f0c488ae2 100644
--- a/src/BinLDrivers/BinLDrivers_DocumentRetrievalDriver.cxx
+++ b/src/BinLDrivers/BinLDrivers_DocumentRetrievalDriver.cxx
@@ -91,7 +91,7 @@ void BinLDrivers_DocumentRetrievalDriver::Read
     TCollection_ExtendedString aFormat = PCDM_ReadWriter::FileFormat (aFileStream, dData);
 
     Read(aFileStream, dData, theNewDocument, theApplication, theProgress);
-    if (theProgress->UserBreak())
+    if (!theProgress.IsNull() && theProgress->UserBreak())
     {
       myReaderStatus = PCDM_RS_UserBreak;
       return;
diff --git a/src/CDF/CDF.cxx b/src/CDF/CDF.cxx
deleted file mode 100644
index ee561708d2..0000000000
--- a/src/CDF/CDF.cxx
+++ /dev/null
@@ -1,39 +0,0 @@
-// Created on: 1998-03-11
-// Created by: Jean-Louis Frenkel
-// Copyright (c) 1998-1999 Matra Datavision
-// Copyright (c) 1999-2014 OPEN CASCADE SAS
-//
-// This file is part of Open CASCADE Technology software library.
-//
-// This library is free software; you can redistribute it and/or modify it under
-// the terms of the GNU Lesser General Public License version 2.1 as published
-// by the Free Software Foundation, with special exception defined in the file
-// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
-// distribution for complete text of the license and disclaimer of any warranty.
-//
-// Alternatively, this file may be used under the terms of Open CASCADE
-// commercial license or contractual agreement.
-
-
-#include <CDF.hxx>
-#include <Standard_Failure.hxx>
-
-static void CDF_InitApplication () {
-
-  static Standard_Boolean FirstApplication = Standard_True;
-
-  if(FirstApplication) {
-    FirstApplication = Standard_False;
-  }
-}
-void CDF::GetLicense(const Standard_Integer ){
-
-  CDF_InitApplication();
-  
-}
-
-Standard_Boolean CDF::IsAvailable(const Standard_Integer ) {
-
-  CDF_InitApplication();
-  return Standard_True;
-}
diff --git a/src/CDF/CDF.hxx b/src/CDF/CDF.hxx
deleted file mode 100644
index b64755101d..0000000000
--- a/src/CDF/CDF.hxx
+++ /dev/null
@@ -1,45 +0,0 @@
-// Created on: 1997-08-07
-// Created by: Jean-Louis Frenkel
-// Copyright (c) 1997-1999 Matra Datavision
-// Copyright (c) 1999-2014 OPEN CASCADE SAS
-//
-// This file is part of Open CASCADE Technology software library.
-//
-// This library is free software; you can redistribute it and/or modify it under
-// the terms of the GNU Lesser General Public License version 2.1 as published
-// by the Free Software Foundation, with special exception defined in the file
-// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
-// distribution for complete text of the license and disclaimer of any warranty.
-//
-// Alternatively, this file may be used under the terms of Open CASCADE
-// commercial license or contractual agreement.
-
-#ifndef _CDF_HeaderFile
-#define _CDF_HeaderFile
-
-#include <Standard.hxx>
-#include <Standard_DefineAlloc.hxx>
-#include <Standard_Handle.hxx>
-
-#include <Standard_Integer.hxx>
-#include <Standard_Boolean.hxx>
-class CDF_Directory;
-class CDF_DirectoryIterator;
-class CDF_Session;
-class CDF_Application;
-class CDF_StoreList;
-class CDF_Store;
-class CDF_MetaDataDriver;
-class CDF_FWOSDriver;
-class CDF_MetaDataDriverFactory;
-
-class CDF 
-{
-public:
-  
-  Standard_EXPORT static void GetLicense (const Standard_Integer anApplicationIdentifier);
-  
-  Standard_EXPORT static Standard_Boolean IsAvailable (const Standard_Integer anApplicationIdentifier);
-};
-
-#endif // _CDF_HeaderFile
diff --git a/src/CDF/CDF_Application.cxx b/src/CDF/CDF_Application.cxx
index ec967fe73e..cb9f02bd47 100644
--- a/src/CDF/CDF_Application.cxx
+++ b/src/CDF/CDF_Application.cxx
@@ -18,8 +18,8 @@
 
 #include <CDF_Application.hxx>
 #include <CDF_Directory.hxx>
-#include <CDF_MetaDataDriver.hxx>
 #include <CDF_Session.hxx>
+#include <CDF_FWOSDriver.hxx>
 #include <CDM_CanCloseStatus.hxx>
 #include <CDM_Document.hxx>
 #include <CDM_MetaData.hxx>
@@ -36,15 +36,15 @@
 #include <Message_ProgressSentry.hxx>
 
 IMPLEMENT_STANDARD_RTTIEXT(CDF_Application,CDM_Application)
-
-#define theMetaDataDriver CDF_Session::CurrentSession()->MetaDataDriver()
-
-
 //=======================================================================
 //function : 
 //purpose  : 
 //=======================================================================
-CDF_Application::CDF_Application():myRetrievableStatus(PCDM_RS_OK) {}
+CDF_Application::CDF_Application():myRetrievableStatus(PCDM_RS_OK) 
+{
+  myDirectory      = new CDF_Directory();
+  myMetaDataDriver = new CDF_FWOSDriver;
+}
 
 //=======================================================================
 //function : Load
@@ -59,7 +59,7 @@ Handle(CDF_Application) CDF_Application::Load(const Standard_GUID& aGUID) {
 //purpose  : 
 //=======================================================================
 void CDF_Application::Open(const Handle(CDM_Document)& aDocument) {
-  CDF_Session::CurrentSession()->Directory()->Add(aDocument);
+  myDirectory->Add(aDocument);
   aDocument->Open(this);
   Activate(aDocument,CDF_TOA_New);
 }
@@ -77,7 +77,7 @@ CDM_CanCloseStatus CDF_Application::CanClose(const Handle(CDM_Document)& aDocume
 //purpose  : 
 //=======================================================================
 void CDF_Application::Close(const Handle(CDM_Document)& aDocument) {
-  CDF_Session::CurrentSession()->Directory()->Remove(aDocument);
+  myDirectory->Remove(aDocument);
   aDocument->Close();
 }
 
@@ -107,15 +107,15 @@ Handle(CDM_Document)  CDF_Application::Retrieve (const TCollection_ExtendedStrin
   Handle(CDM_MetaData) theMetaData; 
   
   if(aVersion.Length() == 0) 
-    theMetaData=theMetaDataDriver->MetaData(aFolder,aName);
+    theMetaData=myMetaDataDriver->MetaData(aFolder,aName);
   else 
-    theMetaData=theMetaDataDriver->MetaData(aFolder,aName,aVersion);
+    theMetaData=myMetaDataDriver->MetaData(aFolder,aName,aVersion);
 
   CDF_TypeOfActivation theTypeOfActivation=TypeOfActivation(theMetaData);
   Handle(CDM_Document) theDocument = Retrieve(theMetaData, UseStorageConfiguration,
                                               Standard_False, theProgress);
 
-  CDF_Session::CurrentSession()->Directory()->Add(theDocument);
+  myDirectory->Add(theDocument);
   Activate(theDocument,theTypeOfActivation);
 
   theDocument->Open(this);
@@ -137,12 +137,12 @@ PCDM_ReaderStatus CDF_Application::CanRetrieve(const TCollection_ExtendedString&
 //=======================================================================
 PCDM_ReaderStatus CDF_Application::CanRetrieve(const TCollection_ExtendedString&  aFolder, const TCollection_ExtendedString&  aName, const TCollection_ExtendedString&  aVersion) {
   
-  if (!theMetaDataDriver->Find(aFolder,aName,aVersion))
+  if (!myMetaDataDriver->Find(aFolder,aName,aVersion))
     return PCDM_RS_UnknownDocument;
-  else if (!theMetaDataDriver->HasReadPermission(aFolder,aName,aVersion))
+  else if (!myMetaDataDriver->HasReadPermission(aFolder,aName,aVersion))
     return PCDM_RS_PermissionDenied;
   else {
-    Handle(CDM_MetaData) theMetaData = theMetaDataDriver->MetaData(aFolder,aName,aVersion);
+    Handle(CDM_MetaData) theMetaData = myMetaDataDriver->MetaData(aFolder,aName,aVersion);
 
     if(theMetaData->IsRetrieved()) {
       return theMetaData->Document()->IsModified()
@@ -190,7 +190,7 @@ void CDF_Application::Activate(const Handle(CDM_Document)& ,const CDF_TypeOfActi
 //=======================================================================
 Standard_ExtString CDF_Application::DefaultFolder(){
   if(myDefaultFolder.Length() == 0) {
-    myDefaultFolder=CDF_Session::CurrentSession()->MetaDataDriver()->DefaultFolder();
+    myDefaultFolder=myMetaDataDriver->DefaultFolder();
   }
   return myDefaultFolder.ToExtString();
 }
@@ -200,7 +200,7 @@ Standard_ExtString CDF_Application::DefaultFolder(){
 //purpose  : 
 //=======================================================================
 Standard_Boolean CDF_Application::SetDefaultFolder(const Standard_ExtString aFolder) {
-  Standard_Boolean found = CDF_Session::CurrentSession()->MetaDataDriver()->FindFolder(aFolder);
+  Standard_Boolean found = myMetaDataDriver->FindFolder(aFolder);
   if(found) myDefaultFolder=aFolder;
   return found;
 }
@@ -271,7 +271,7 @@ Handle(CDM_Document) CDF_Application::Retrieve (const Handle(CDM_MetaData)& aMet
     SetReferenceCounter(theDocument,PCDM_RetrievalDriver::ReferenceCounter(aMetaData->FileName(), MessageDriver()));
     
     SetDocumentVersion(theDocument,aMetaData);
-    theMetaDataDriver->ReferenceIterator()->LoadReferences(theDocument,aMetaData,this,UseStorageConfiguration);
+    myMetaDataDriver->ReferenceIterator()->LoadReferences(theDocument,aMetaData,this,UseStorageConfiguration);
 
     try {    
       OCC_CATCH_SIGNALS
@@ -530,3 +530,12 @@ PCDM_ReaderStatus CDF_Application::CanRetrieve(const Handle(CDM_MetaData)& aMeta
   else
     return CanRetrieve(aMetaData->Folder(),aMetaData->Name());
 }
+
+//=======================================================================
+//function : MetaDataDriver
+//purpose  :
+//=======================================================================
+Handle(CDF_MetaDataDriver) CDF_Application::MetaDataDriver() const {
+  Standard_NoSuchObject_Raise_if(myMetaDataDriver.IsNull(), "no metadatadriver has been provided; this application is not able to store or retrieve files.");
+  return myMetaDataDriver;
+}
diff --git a/src/CDF/CDF_Application.hxx b/src/CDF/CDF_Application.hxx
index 2b599c55ca..247cfb5d01 100644
--- a/src/CDF/CDF_Application.hxx
+++ b/src/CDF/CDF_Application.hxx
@@ -19,10 +19,11 @@
 
 #include <TCollection_ExtendedString.hxx>
 #include <PCDM_ReaderStatus.hxx>
+#include <CDF_TypeOfActivation.hxx>
+#include <CDF_MetaDataDriver.hxx>
 #include <CDM_Application.hxx>
 #include <CDM_CanCloseStatus.hxx>
 #include <TColStd_SequenceOfExtendedString.hxx>
-#include <CDF_TypeOfActivation.hxx>
 #include <Standard_IStream.hxx>
 #include <NCollection_IndexedDataMap.hxx>
 
@@ -35,7 +36,7 @@ class PCDM_Reader;
 class CDM_MetaData;
 class PCDM_RetrievalDriver;
 class PCDM_StorageDriver;
-
+class CDF_Directory;
 class CDF_Application;
 DEFINE_STANDARD_HANDLE(CDF_Application, CDM_Application)
 
@@ -167,12 +168,17 @@ public:
   Standard_EXPORT Standard_ExtString DefaultFolder();
   
   Standard_EXPORT Standard_Boolean SetDefaultFolder (const Standard_ExtString aFolder);
-  
+
+  //! returns MetaDatdDriver of this application
+  Standard_EXPORT Handle(CDF_MetaDataDriver) MetaDataDriver() const;
+
 friend class CDF_Session;
 
 
   DEFINE_STANDARD_RTTIEXT(CDF_Application,CDM_Application)
 
+  Handle(CDF_MetaDataDriver) myMetaDataDriver;
+  Handle(CDF_Directory) myDirectory;
 private:
 
   
diff --git a/src/CDF/CDF_Directory.cxx b/src/CDF/CDF_Directory.cxx
index c4ed91ca72..cb1952692e 100644
--- a/src/CDF/CDF_Directory.cxx
+++ b/src/CDF/CDF_Directory.cxx
@@ -31,31 +31,22 @@ void CDF_Directory::Add(const Handle(CDM_Document)& aDocument) {
 }
 
 void CDF_Directory::Remove(const Handle(CDM_Document)& aDocument) {
-
-  CDM_ListIteratorOfListOfDocument it(myDocuments);
-  
-  Standard_Boolean found = Standard_False;
-  for (; it.More() && !found;) {
-    found = aDocument == it.Value();
-    if(found) 
+  for (CDM_ListIteratorOfListOfDocument it(myDocuments); it.More(); it.Next()) {
+    if (aDocument == it.Value()) {
       myDocuments.Remove(it);
-    else
-      it.Next();
+      break;
+    }
   }
 }
 
-
 Standard_Boolean CDF_Directory::Contains(const Handle(CDM_Document)& aDocument) const {
-
-  CDM_ListIteratorOfListOfDocument it(myDocuments);
-  Standard_Boolean found = Standard_False;
-  for (; it.More() && !found; it.Next()) {
-    found = aDocument == it.Value();
+  for (CDM_ListIteratorOfListOfDocument it(myDocuments); it.More(); it.Next()) {
+    if (aDocument == it.Value())
+      return Standard_True;
   }
-  return found;
+  return Standard_False;
 }
 
-
 Standard_Integer CDF_Directory::Length() const {
   return myDocuments.Extent();
 }
@@ -69,6 +60,7 @@ const CDM_ListOfDocument& CDF_Directory::List() const {
 Standard_Boolean CDF_Directory::IsEmpty() const {
   return myDocuments.IsEmpty();
 }
+
 Handle(CDM_Document) CDF_Directory::Last() {
   Standard_NoSuchObject_Raise_if(IsEmpty(),"CDF_Directory::Last: the directory does not contain any document");
   return myDocuments.Last();
diff --git a/src/CDF/CDF_DirectoryIterator.cxx b/src/CDF/CDF_DirectoryIterator.cxx
index b8575a9c3a..d04cd8b9a9 100644
--- a/src/CDF/CDF_DirectoryIterator.cxx
+++ b/src/CDF/CDF_DirectoryIterator.cxx
@@ -21,9 +21,6 @@
 #include <CDM_Document.hxx>
 #include <Standard_NoSuchObject.hxx>
 
-CDF_DirectoryIterator::CDF_DirectoryIterator():myIterator(CDF_Session::CurrentSession()->Directory()->List()) {}
-
-
 
 CDF_DirectoryIterator::CDF_DirectoryIterator(const Handle(CDF_Directory)& aDirectory):myIterator(aDirectory->List()) {}
 
diff --git a/src/CDF/CDF_MetaDataDriver.cxx b/src/CDF/CDF_MetaDataDriver.cxx
index 9ca76e7f73..5fb970e969 100644
--- a/src/CDF/CDF_MetaDataDriver.cxx
+++ b/src/CDF/CDF_MetaDataDriver.cxx
@@ -24,6 +24,7 @@
 #include <Standard_NotImplemented.hxx>
 #include <Standard_Type.hxx>
 #include <TCollection_ExtendedString.hxx>
+#include <OSD_Thread.hxx>
 
 IMPLEMENT_STANDARD_RTTIEXT(CDF_MetaDataDriver,Standard_Transient)
 
@@ -68,7 +69,8 @@ void CDF_MetaDataDriver::CreateDependsOn(const Handle(CDM_MetaData)& ,
 //purpose  : 
 //=======================================================================
 
-void CDF_MetaDataDriver::CreateReference(const Handle(CDM_MetaData)& ,const Handle(CDM_MetaData)& , const Standard_Integer , const Standard_Integer ) {}
+void CDF_MetaDataDriver::CreateReference(const Handle(CDM_MetaData)& ,
+  const Handle(CDM_MetaData)& , const Standard_Integer , const Standard_Integer ) {}
 
 //=======================================================================
 //function : ReferenceIterator
@@ -76,7 +78,10 @@ void CDF_MetaDataDriver::CreateReference(const Handle(CDM_MetaData)& ,const Hand
 //=======================================================================
 
 Handle(PCDM_ReferenceIterator) CDF_MetaDataDriver::ReferenceIterator() {
-  return new PCDM_ReferenceIterator(CDF_Session::CurrentSession()->CurrentApplication()->MessageDriver());
+  Standard_ThreadId anID = OSD_Thread::Current();
+  Handle(CDF_Application) anApp; 
+  CDF_Session::CurrentSession()->FindApplication(anID, anApp);
+  return new PCDM_ReferenceIterator(anApp->MessageDriver());
 }
 
 //=======================================================================
@@ -84,7 +89,9 @@ Handle(PCDM_ReferenceIterator) CDF_MetaDataDriver::ReferenceIterator() {
 //purpose  : 
 //=======================================================================
 
-Standard_Boolean CDF_MetaDataDriver::Find(const TCollection_ExtendedString& aFolder, const TCollection_ExtendedString& aName) {
+Standard_Boolean CDF_MetaDataDriver::Find(const TCollection_ExtendedString& aFolder, 
+  const TCollection_ExtendedString& aName) 
+{
   TCollection_ExtendedString aVersion;
   return Find(aFolder,aName,aVersion);
 }
diff --git a/src/CDF/CDF_Session.cxx b/src/CDF/CDF_Session.cxx
index 7c15099888..91e6eb7574 100644
--- a/src/CDF/CDF_Session.cxx
+++ b/src/CDF/CDF_Session.cxx
@@ -34,17 +34,28 @@
 
 IMPLEMENT_STANDARD_RTTIEXT(CDF_Session,Standard_Transient)
 
-static Handle(CDF_Session) CS;
+static Handle(CDF_Session) THE_CS;
+static Standard_Mutex THE_MUTEX;
 
 //=======================================================================
 //function : 
 //purpose  : 
 //=======================================================================
-CDF_Session::CDF_Session () : myHasCurrentApplication(Standard_False)
+CDF_Session::CDF_Session ()
 {  
-  Standard_MultiplyDefined_Raise_if(!CS.IsNull()," a session already exists");
-  myDirectory = new CDF_Directory();
-  CS = this;
+  Standard_MultiplyDefined_Raise_if(!THE_CS.IsNull()," a session already exists");
+}
+
+//=======================================================================
+//function : 
+//purpose  : 
+//=======================================================================
+Handle(CDF_Session) CDF_Session::Create()
+{
+  Standard_Mutex::Sentry aLocker(THE_MUTEX);
+  if (THE_CS.IsNull())
+    THE_CS = new CDF_Session;
+  return THE_CS;
 }
 
 //=======================================================================
@@ -52,16 +63,7 @@ CDF_Session::CDF_Session () : myHasCurrentApplication(Standard_False)
 //purpose  : 
 //=======================================================================
 Standard_Boolean CDF_Session::Exists() {
-  return !CS.IsNull();
-}
-
-//=======================================================================
-//function : Directory
-//purpose  : 
-//=======================================================================
-Handle(CDF_Directory) CDF_Session::Directory() const {
-  
-  return CS->myDirectory;
+  return !THE_CS.IsNull();
 }
 
 //=======================================================================
@@ -69,63 +71,65 @@ Handle(CDF_Directory) CDF_Session::Directory() const {
 //purpose  : 
 //=======================================================================
 Handle(CDF_Session) CDF_Session::CurrentSession() {
-  Standard_NoSuchObject_Raise_if(CS.IsNull(), "no session has been created");
-  return CS;
+  Standard_NoSuchObject_Raise_if(THE_CS.IsNull(), "no session has been created");
+  return THE_CS;
 }
 
 //=======================================================================
-//function : HasCurrentApplication
-//purpose  : 
+//function : AddApplication
+//purpose  : adds the application to the session with unique name
 //=======================================================================
-Standard_Boolean CDF_Session::HasCurrentApplication() const {
-  return myHasCurrentApplication;
+Standard_Boolean CDF_Session::AddApplication(const Handle(CDF_Application)& theApp,
+  const Standard_ThreadId theID)
+{
+  return AddApplication(theApp.get(), theID);
 }
 
 //=======================================================================
-//function : CurrentApplication
-//purpose  : 
+//function : AddApplication
+//purpose  : adds the application to the session with unique name
 //=======================================================================
-Handle(CDF_Application) CDF_Session::CurrentApplication() const {
-  Standard_NoSuchObject_Raise_if(!myHasCurrentApplication,"there is no current application in the session");
-  return myCurrentApplication;
-}
-
-//=======================================================================
-//function : SetCurrentApplication
-//purpose  : 
-//=======================================================================
-void CDF_Session::SetCurrentApplication(const Handle(CDF_Application)& anApplication) {
-  myCurrentApplication  = anApplication;
-  myHasCurrentApplication = Standard_True;
-}
-
-//=======================================================================
-//function : UnsetCurrentApplication
-//purpose  : 
-//=======================================================================
-void CDF_Session::UnsetCurrentApplication() {
-  myHasCurrentApplication = Standard_False;
-  myCurrentApplication.Nullify();
-}
-
-//=======================================================================
-//function : MetaDataDriver
-//purpose  : 
-//=======================================================================
-Handle(CDF_MetaDataDriver) CDF_Session::MetaDataDriver() const {
-  Standard_NoSuchObject_Raise_if(myMetaDataDriver.IsNull(),"no metadatadriver has been provided; this session is not able to store or retrieve files.");
-  return myMetaDataDriver;
-}
-
-//=======================================================================
-//function : LoadDriver
-//purpose  : 
-//=======================================================================
-void CDF_Session::LoadDriver() {
-  if (myMetaDataDriver.IsNull()) {
-    // for compatibility with old code, initialize useless driver directly
-    // instead of loading it as plugin
-    Handle(CDF_MetaDataDriverFactory) aFactory;
-    myMetaDataDriver = new CDF_FWOSDriver;
+Standard_Boolean CDF_Session::AddApplication(const CDF_Application* theApp,
+  const Standard_ThreadId theID)
+{
+  Standard_Boolean aRetValue(Standard_False);
+  if (theApp)
+  {
+    Standard_Mutex::Sentry aLocker(THE_MUTEX);
+    if (!myAppDirectory.IsBound(theID))
+    {
+      Handle(CDF_Application) anApp(theApp);
+      aRetValue = myAppDirectory.Bind(theID, anApp);
+    }
   }
+  return aRetValue;
+}
+
+//=======================================================================
+//function : FindApplication
+//purpose  : 
+//=======================================================================
+Standard_Boolean CDF_Session::FindApplication(const Standard_ThreadId theID, Handle(CDF_Application)& theApp) const
+{
+  Standard_Mutex::Sentry aLocker(THE_MUTEX);
+  if (myAppDirectory.IsBound(theID))
+  {
+    theApp = Handle(CDF_Application)::DownCast (myAppDirectory.Find(theID));
+    return ! theApp.IsNull();
+  }
+  return Standard_False;
+}
+//=======================================================================
+//function : RemoveApplication
+//purpose  : removes the application with name=<theName> from the session
+//=======================================================================
+Standard_Boolean CDF_Session::RemoveApplication(const Standard_ThreadId theID)
+{
+  Standard_Boolean aRetValue(Standard_False);
+  Standard_Mutex::Sentry aLocker(THE_MUTEX);
+  if (myAppDirectory.IsBound(theID))
+  {
+    aRetValue = myAppDirectory.UnBind(theID);
+  }
+  return aRetValue;
 }
diff --git a/src/CDF/CDF_Session.hxx b/src/CDF/CDF_Session.hxx
index 0f74b323c8..ce5c3cd46f 100644
--- a/src/CDF/CDF_Session.hxx
+++ b/src/CDF/CDF_Session.hxx
@@ -22,13 +22,14 @@
 
 #include <Standard_Boolean.hxx>
 #include <Standard_Transient.hxx>
+#include <Standard_Mutex.hxx>
+#include <CDM_ApplicationDirectory.hxx>
 class CDF_Directory;
 class CDF_Application;
 class CDF_MetaDataDriver;
 class Standard_NoSuchObject;
 class Standard_MultiplyDefined;
 
-
 class CDF_Session;
 DEFINE_STANDARD_HANDLE(CDF_Session, Standard_Transient)
 
@@ -39,29 +40,27 @@ class CDF_Session : public Standard_Transient
 public:
 
   
-  Standard_EXPORT CDF_Session();
-  
   //! returns true if a session has been created.
   Standard_EXPORT static Standard_Boolean Exists();
-  
+
+  //! Creates a session if it does not exists yet
+  Standard_EXPORT static Handle(CDF_Session) Create();
+
   //! returns the only one instance of Session
   //! that has been created.
   Standard_EXPORT static Handle(CDF_Session) CurrentSession();
   
-  //! returns the directory of the session;
-  Standard_EXPORT Handle(CDF_Directory) Directory() const;
-  
-  Standard_EXPORT Standard_Boolean HasCurrentApplication() const;
-  
-  Standard_EXPORT Handle(CDF_Application) CurrentApplication() const;
-  
-  Standard_EXPORT void SetCurrentApplication (const Handle(CDF_Application)& anApplication);
-  
-  Standard_EXPORT void UnsetCurrentApplication();
-  
-  Standard_EXPORT Handle(CDF_MetaDataDriver) MetaDataDriver() const;
-  
-  Standard_EXPORT void LoadDriver();
+  //! returns true if theApp is added to the session
+  Standard_EXPORT Standard_Boolean AddApplication(const Handle(CDF_Application)& theApp, const Standard_ThreadId theID);
+
+  //! returns true if theApp is added to the session
+  Standard_EXPORT Standard_Boolean AddApplication(const CDF_Application* theApp, const Standard_ThreadId theID);
+
+  //! returns true if theApp is removed from the session
+  Standard_EXPORT Standard_Boolean RemoveApplication(const Standard_ThreadId theID);
+
+  //! returns true if theApp is removed from the session
+  Standard_EXPORT Standard_Boolean FindApplication(const Standard_ThreadId, Handle(CDF_Application)& theApp) const;
 
 
 friend class CDF_Application;
@@ -71,18 +70,17 @@ friend class CDF_Application;
 
 protected:
 
+  //! Use "Create" session for creation of an instance
+  CDF_Session();
+
 
 
 
 private:
 
 
-  Handle(CDF_Directory) myDirectory;
-  Handle(CDF_Application) myCurrentApplication;
-  Standard_Boolean myHasCurrentApplication;
+  CDM_ApplicationDirectory myAppDirectory;
   Handle(CDF_MetaDataDriver) myMetaDataDriver;
-
-
 };
 
 
diff --git a/src/CDF/CDF_Store.cxx b/src/CDF/CDF_Store.cxx
index fe91752b4e..7098df58fc 100644
--- a/src/CDF/CDF_Store.cxx
+++ b/src/CDF/CDF_Store.cxx
@@ -25,14 +25,10 @@
 #include <PCDM_StorageDriver.hxx>
 #include <PCDM_StoreStatus.hxx>
 #include <Standard_ProgramError.hxx>
-#include <TCollection_ExtendedString.hxx>
-
-#define theMetaDataDriver CDF_Session::CurrentSession()->MetaDataDriver()
-
-
-static TCollection_ExtendedString blank("");
 
+#define theMetaDataDriver Handle(CDF_Application)::DownCast((myCurrentDocument->Application()))->MetaDataDriver()
 
+static const Handle(TCollection_HExtendedString) blank = new TCollection_HExtendedString("");
 
 CDF_Store::CDF_Store()
 : myHasSubComponents(Standard_False),
@@ -67,19 +63,14 @@ void CDF_Store::Init() {
   myCurrentDocument = myMainDocument;
 }
 
-Standard_ExtString CDF_Store::Folder() const {
-  static TCollection_ExtendedString retv;
+Handle(TCollection_HExtendedString) CDF_Store::Folder() const {
   if(myCurrentDocument->HasRequestedFolder())
-    retv =  myCurrentDocument->RequestedFolder();
-  else
-    retv= blank;
-  return retv.ToExtString();
+    return new TCollection_HExtendedString(myCurrentDocument->RequestedFolder());
+  return blank;
 }
 
-Standard_ExtString CDF_Store::Name() const {
-  static TCollection_ExtendedString retv;
-  retv = myCurrentDocument->RequestedName();
-  return retv.ToExtString();
+Handle(TCollection_HExtendedString) CDF_Store::Name() const {
+  return new TCollection_HExtendedString(myCurrentDocument->RequestedName());
 }
 
 
@@ -156,21 +147,15 @@ void CDF_Store::Realize (const Handle(Message_ProgressIndicator)& theProgress)
 Standard_ExtString CDF_Store::Path() const {
   return myPath.ToExtString();
 }
-Standard_ExtString CDF_Store::MetaDataPath() const {
-  static TCollection_ExtendedString retv;
-  retv="";
-  if(myCurrentDocument->IsStored()) retv=myCurrentDocument->MetaData()->Path();
-  return retv.ToExtString();
+Handle(TCollection_HExtendedString) CDF_Store::MetaDataPath() const {
+  if(myCurrentDocument->IsStored())
+    return new TCollection_HExtendedString(myCurrentDocument->MetaData()->Path());
+  return blank;
 }
-Standard_ExtString CDF_Store::Description() const {
-  static TCollection_ExtendedString retv;
-
+Handle(TCollection_HExtendedString) CDF_Store::Description() const {
   if(myMainDocument->FindDescription())
-    retv = myMainDocument->Description();
-  else
-    retv= blank;
-
-  return retv.ToExtString();
+    return new TCollection_HExtendedString(myMainDocument->Description());
+  return blank;
 }
 
 Standard_Boolean CDF_Store::IsStored() const {
@@ -192,13 +177,10 @@ Standard_Boolean CDF_Store::HasAPreviousVersion() const {
   return myCurrentDocument->HasRequestedPreviousVersion();
 }
 
-Standard_ExtString CDF_Store::PreviousVersion() const {
-  static TCollection_ExtendedString retv;
+Handle(TCollection_HExtendedString) CDF_Store::PreviousVersion() const {
   if(myCurrentDocument->HasRequestedPreviousVersion())
-    retv= myCurrentDocument->RequestedPreviousVersion();
-  else
-    retv=blank;
-  return retv.ToExtString();
+    return new TCollection_HExtendedString(myCurrentDocument->RequestedPreviousVersion());
+  return blank;
 }
 
 Standard_Boolean CDF_Store::SetPreviousVersion (const Standard_ExtString aPreviousVersion) {
@@ -218,36 +200,7 @@ Standard_Boolean CDF_Store::SetPreviousVersion (const Standard_ExtString aPrevio
   return Standard_True;
 }
 
-void CDF_Store::InitComponent() {
-   myList->Init();
-}
-
-Standard_Boolean CDF_Store::MoreComponent() const {
-  return myList->More();
-}
-
-void CDF_Store::NextComponent()  {
-  myList->Next();
-}
-void CDF_Store::SetCurrent() {
-  myCurrentDocument = myList->Value();
-  myIsMainDocument = myCurrentDocument == myMainDocument;
-
-
-}
-
-Standard_ExtString CDF_Store::Component() const {
-  
-  static TCollection_ExtendedString retv;
-  retv=myList->Value()->Presentation();
-  return retv.ToExtString();
-}
-Standard_Boolean CDF_Store::HasSubComponents () const {
-   return myHasSubComponents;
-}
-
-void CDF_Store::SetCurrent(const Standard_ExtString aPresentation) {
-  myCurrentDocument = CDM_Document::FindFromPresentation(aPresentation);
+void CDF_Store::SetCurrent(const Standard_ExtString /*aPresentation*/) {
   myIsMainDocument = myCurrentDocument == myMainDocument;
 }
 void CDF_Store::SetMain() {
@@ -259,18 +212,6 @@ Standard_Boolean CDF_Store::IsMainDocument() const {
   return myIsMainDocument;
 }
 
-CDF_SubComponentStatus CDF_Store::SubComponentStatus(const Standard_ExtString aPresentation) const {
-   Handle(CDM_Document) d = CDM_Document::FindFromPresentation(aPresentation);
-
-  if(!d->IsStored()) 
-    return d->HasRequestedFolder()? CDF_SCS_Consistent : CDF_SCS_Unconsistent;
-
-  if(d->IsModified()) return CDF_SCS_Modified;
-  return CDF_SCS_Stored;
-}
-
-
-
 PCDM_StoreStatus CDF_Store::StoreStatus() const {
   return myStatus;
 }
@@ -281,8 +222,7 @@ Standard_ExtString CDF_Store::AssociatedStatusText() const {
 
 void CDF_Store::FindDefault() {
   if (!myCurrentDocument->IsStored ()) {
-    myCurrentDocument->SetRequestedFolder(CDF_Session::CurrentSession()->CurrentApplication()->DefaultFolder());
-//    myCurrentDocument->SetRequestedName(theMetaDataDriver->SetName(myCurrentDocument,myCurrentDocument->Presentation()));
+    myCurrentDocument->SetRequestedFolder(Handle(CDF_Application)::DownCast((myCurrentDocument->Application()))->DefaultFolder());
     myCurrentDocument->SetRequestedName(theMetaDataDriver->SetName(myCurrentDocument,myCurrentDocument->RequestedName()));
   }
 }
@@ -290,8 +230,6 @@ void CDF_Store::SetComment(const Standard_ExtString aComment) {
   myCurrentDocument->SetRequestedComment(aComment);
 }
 
-Standard_ExtString CDF_Store::Comment() const {
-  static TCollection_ExtendedString retv;
-  retv=myCurrentDocument->RequestedComment();
-  return retv.ToExtString();
+Handle(TCollection_HExtendedString) CDF_Store::Comment() const {
+  return new TCollection_HExtendedString(myCurrentDocument->RequestedComment());
 }
diff --git a/src/CDF/CDF_Store.hxx b/src/CDF/CDF_Store.hxx
index 66e03a37be..3476344f59 100644
--- a/src/CDF/CDF_Store.hxx
+++ b/src/CDF/CDF_Store.hxx
@@ -28,6 +28,7 @@
 #include <Standard_ExtString.hxx>
 #include <CDF_StoreSetNameStatus.hxx>
 #include <CDF_SubComponentStatus.hxx>
+#include <TCollection_HExtendedString.hxx>
 
 #include <Message_ProgressIndicator.hxx>
 
@@ -48,10 +49,10 @@ public:
   Standard_EXPORT CDF_Store(const Handle(CDM_Document)& aDocument);
   
   //! returns the folder in which the current document will be stored.
-  Standard_EXPORT Standard_ExtString Folder() const;
+  Standard_EXPORT Handle(TCollection_HExtendedString) Folder() const;
   
   //! returns the name under which the current document will be stored
-  Standard_EXPORT Standard_ExtString Name() const;
+  Standard_EXPORT Handle(TCollection_HExtendedString) Name() const;
   
   //! returns true if the current document is already stored
   Standard_EXPORT Standard_Boolean IsStored() const;
@@ -64,7 +65,7 @@ public:
   
   Standard_EXPORT Standard_Boolean HasAPreviousVersion() const;
   
-  Standard_EXPORT Standard_ExtString PreviousVersion() const;
+  Standard_EXPORT Handle(TCollection_HExtendedString) PreviousVersion() const;
   
   //! returns true if the currentdocument is the main one, ie the document
   //! of the current selection.
@@ -80,7 +81,7 @@ public:
   
   Standard_EXPORT void SetComment (const Standard_ExtString aComment);
   
-  Standard_EXPORT Standard_ExtString Comment() const;
+  Standard_EXPORT Handle(TCollection_HExtendedString) Comment() const;
   
   //! defines the name under which the document should be stored.
   //! uses for example after modification of the folder.
@@ -95,29 +96,10 @@ public:
   
   //! returns the path of  the previous store is the object
   //! is already stored, otherwise an empty string;
-  Standard_EXPORT Standard_ExtString MetaDataPath() const;
+  Standard_EXPORT Handle(TCollection_HExtendedString) MetaDataPath() const;
   
   //! returns the description of the format of the main object.
-  Standard_EXPORT Standard_ExtString Description() const;
-  
-  //! Allows to Start a new Iteration from beginning
-  Standard_EXPORT void InitComponent();
-  
-  //! Returns True if there are more entries to return
-  Standard_EXPORT Standard_Boolean MoreComponent() const;
-  
-  //! Go to the next entry
-  //! (if there is not, Value will raise an exception)
-  Standard_EXPORT void NextComponent();
-  
-  Standard_EXPORT void SetCurrent();
-  
-  //! Returns item value of current entry
-  Standard_EXPORT Standard_ExtString Component() const;
-  
-  Standard_EXPORT Standard_Boolean HasSubComponents() const;
-  
-  Standard_EXPORT CDF_SubComponentStatus SubComponentStatus (const Standard_ExtString aPresentation) const;
+  Standard_EXPORT Handle(TCollection_HExtendedString) Description() const;
   
   Standard_EXPORT void SetCurrent (const Standard_ExtString aPresentation);
   
diff --git a/src/CDF/CDF_StoreList.cxx b/src/CDF/CDF_StoreList.cxx
index 24d399771c..ae087dfc55 100644
--- a/src/CDF/CDF_StoreList.cxx
+++ b/src/CDF/CDF_StoreList.cxx
@@ -78,7 +78,7 @@ PCDM_StoreStatus CDF_StoreList::Store (Handle(CDM_MetaData)& aMetaData,
                                       TCollection_ExtendedString& aStatusAssociatedText, 
                                       const Handle(Message_ProgressIndicator)& theProgress)
 {
-  Handle(CDF_MetaDataDriver) theMetaDataDriver = CDF_Session::CurrentSession()->MetaDataDriver();
+  Handle(CDF_MetaDataDriver) theMetaDataDriver = Handle(CDF_Application)::DownCast((myMainDocument->Application()))->MetaDataDriver();
 
   PCDM_StoreStatus status = PCDM_SS_OK;
   {
diff --git a/src/CDF/FILES b/src/CDF/FILES
index d0aa8b6da7..d29b79d6bd 100755
--- a/src/CDF/FILES
+++ b/src/CDF/FILES
@@ -1,5 +1,3 @@
-CDF.cxx
-CDF.hxx
 CDF_Application.cxx
 CDF_Application.hxx
 CDF_Directory.cxx
diff --git a/src/CDM/CDM_Application.cxx b/src/CDM/CDM_Application.cxx
index c9f9984eca..9bf5de6036 100644
--- a/src/CDM/CDM_Application.cxx
+++ b/src/CDM/CDM_Application.cxx
@@ -28,6 +28,14 @@
 
 IMPLEMENT_STANDARD_RTTIEXT(CDM_Application,Standard_Transient)
 
+//=======================================================================
+//function : Constructor
+//purpose  : 
+//=======================================================================
+CDM_Application::CDM_Application()
+{
+  myMessenger = new Message_Messenger;
+}
 //=======================================================================
 //function : SetDocumentVersion
 //purpose  : 
@@ -58,10 +66,7 @@ void CDM_Application::SetReferenceCounter
 
 Handle(Message_Messenger) CDM_Application::MessageDriver()
 {
-  static Handle(Message_Messenger) theMessenger;
-  if(theMessenger.IsNull()) 
-    theMessenger = Message::DefaultMessenger();
-  return theMessenger;
+  return myMessenger;
 }
 
 //=======================================================================
@@ -79,10 +84,10 @@ void CDM_Application::Write(const Standard_ExtString aString)
 //purpose  : 
 //=======================================================================
 
-void CDM_Application::BeginOfUpdate (const Handle(CDM_Document)& aDocument)
+void CDM_Application::BeginOfUpdate (const Handle(CDM_Document)& /*aDocument*/)
 {
-  TCollection_ExtendedString updating("Updating:");
-  updating+=aDocument->Presentation();
+  TCollection_ExtendedString updating("Updating: ");
+  updating += "Document";
   Write(updating.ToExtString());
 }
 
@@ -92,17 +97,17 @@ void CDM_Application::BeginOfUpdate (const Handle(CDM_Document)& aDocument)
 //=======================================================================
 
 void CDM_Application::EndOfUpdate
-                        (const Handle(CDM_Document)&       aDocument,
+                        (const Handle(CDM_Document)&       /*aDocument*/,
                          const Standard_Boolean            theStatus,
                          const TCollection_ExtendedString& /*ErrorString*/)
 {
   TCollection_ExtendedString message;
   if (theStatus)
-    message="Updated:";
+    message="Updated: ";
   else
-    message="Error during updating:";
+    message="Error during updating: ";
       
-  message+=aDocument->Presentation();
+  message+="Document";
   Write(message.ToExtString());
 }
 
@@ -128,6 +133,15 @@ TCollection_AsciiString CDM_Application::Version() const
   return TCollection_AsciiString();
 }
 
+//=======================================================================
+//function : MetaDataLookUpTable
+//purpose  : returns the MetaData LookUpTable
+//=======================================================================
+CDM_MetaDataLookUpTable* CDM_Application::MetaDataLookUpTable()
+{
+  return &myMetaDataLookUpTable;
+}
+
 //=======================================================================
 //function : DumpJson
 //purpose  : 
diff --git a/src/CDM/CDM_Application.hxx b/src/CDM/CDM_Application.hxx
index d936faf133..f2edf63a10 100644
--- a/src/CDM/CDM_Application.hxx
+++ b/src/CDM/CDM_Application.hxx
@@ -26,6 +26,7 @@
 #include <Standard_ExtString.hxx>
 #include <TCollection_AsciiString.hxx>
 #include <TCollection_ExtendedString.hxx>
+#include <CDM_MetaDataLookUpTable.hxx>
 #include <Message_ProgressIndicator.hxx>
 
 class CDM_Reference;
@@ -68,6 +69,9 @@ public:
   //! Returns the application version.
   Standard_EXPORT virtual TCollection_AsciiString Version() const;
   
+  //! Returns MetaData LookUpTable
+  Standard_EXPORT virtual  CDM_MetaDataLookUpTable* MetaDataLookUpTable();
+
   //! Dumps the content of me into the stream
   Standard_EXPORT void DumpJson (Standard_OStream& theOStream, Standard_Integer theDepth = -1) const;
 
@@ -79,13 +83,12 @@ friend class CDM_MetaData;
 
 protected:
 
-  
+  Standard_EXPORT CDM_Application();
+
   Standard_EXPORT void SetDocumentVersion (const Handle(CDM_Document)& aDocument, const Handle(CDM_MetaData)& aMetaData) const;
   
   Standard_EXPORT void SetReferenceCounter (const Handle(CDM_Document)& aDocument, const Standard_Integer aReferenceCounter);
 
-
-
 private:
 
   
@@ -97,7 +100,8 @@ private:
   //! returns -1 if the metadata has no modification counter.
   Standard_EXPORT virtual Standard_Integer DocumentVersion (const Handle(CDM_MetaData)& aMetaData) = 0;
 
-
+  Handle(Message_Messenger) myMessenger;
+  CDM_MetaDataLookUpTable myMetaDataLookUpTable;
 
 };
 
diff --git a/src/CDM/CDM_PresentationDirectory.hxx b/src/CDM/CDM_ApplicationDirectory.hxx
similarity index 58%
rename from src/CDM/CDM_PresentationDirectory.hxx
rename to src/CDM/CDM_ApplicationDirectory.hxx
index 42786b13f2..cfd00c19de 100644
--- a/src/CDM/CDM_PresentationDirectory.hxx
+++ b/src/CDM/CDM_ApplicationDirectory.hxx
@@ -14,16 +14,17 @@
 // Alternatively, this file may be used under the terms of Open CASCADE
 // commercial license or contractual agreement.
 
-#ifndef CDM_PresentationDirectory_HeaderFile
-#define CDM_PresentationDirectory_HeaderFile
+#ifndef CDM_ApplicationDirectory_HeaderFile
+#define CDM_ApplicationDirectory_HeaderFile
 
-#include <TCollection_ExtendedString.hxx>
-#include <CDM_Document.hxx>
-#include <TCollection_ExtendedString.hxx>
+#include <CDM_Application.hxx>
+#include <TColStd_MapIntegerHasher.hxx>
 #include <NCollection_DataMap.hxx>
+#include <Standard_ThreadId.hxx>
+#include <NCollection_DefaultHasher.hxx>
 
-typedef NCollection_DataMap<TCollection_ExtendedString,Handle(CDM_Document),TCollection_ExtendedString> CDM_PresentationDirectory;
-typedef NCollection_DataMap<TCollection_ExtendedString,Handle(CDM_Document),TCollection_ExtendedString>::Iterator CDM_DataMapIteratorOfPresentationDirectory;
-
+typedef NCollection_DefaultHasher<Standard_ThreadId> CDM_MapThreadIDHasher;
+typedef NCollection_DataMap<Standard_ThreadId,Handle(CDM_Application),CDM_MapThreadIDHasher> CDM_ApplicationDirectory;
+typedef NCollection_DataMap<Standard_ThreadId,Handle(CDM_Application),CDM_MapThreadIDHasher>::Iterator CDM_DataMapIteratorOfApplicationDirectory;
 
 #endif
diff --git a/src/CDM/CDM_DataMapIteratorOfPresentationDirectory.hxx b/src/CDM/CDM_DataMapIteratorOfPresentationDirectory.hxx
deleted file mode 100644
index eb8b09b38a..0000000000
--- a/src/CDM/CDM_DataMapIteratorOfPresentationDirectory.hxx
+++ /dev/null
@@ -1,20 +0,0 @@
-// Copyright (c) 2015 OPEN CASCADE SAS
-//
-// This file is part of Open CASCADE Technology software library.
-//
-// This library is free software; you can redistribute it and/or modify it under
-// the terms of the GNU Lesser General Public License version 2.1 as published
-// by the Free Software Foundation, with special exception defined in the file
-// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
-// distribution for complete text of the license and disclaimer of any warranty.
-//
-// Alternatively, this file may be used under the terms of Open CASCADE
-// commercial license or contractual agreement.
-
-
-#ifndef CDM_DataMapIteratorOfPresentationDirectory_HeaderFile
-#define CDM_DataMapIteratorOfPresentationDirectory_HeaderFile
-
-#include <CDM_PresentationDirectory.hxx>
-
-#endif
diff --git a/src/CDM/CDM_Document.cxx b/src/CDM/CDM_Document.cxx
index 0ec0acc66d..189203218b 100644
--- a/src/CDM/CDM_Document.cxx
+++ b/src/CDM/CDM_Document.cxx
@@ -23,7 +23,6 @@
 #include <CDM_ListOfDocument.hxx>
 #include <CDM_MetaData.hxx>
 #include <CDM_NamesDirectory.hxx>
-#include <CDM_PresentationDirectory.hxx>
 #include <CDM_Reference.hxx>
 #include <CDM_ReferenceIterator.hxx>
 #include <Resource_Manager.hxx>
@@ -40,11 +39,6 @@
 
 IMPLEMENT_STANDARD_RTTIEXT(CDM_Document,Standard_Transient)
 
-static CDM_PresentationDirectory& getPresentations() {
-  static CDM_PresentationDirectory thePresentations;
-  return thePresentations;
-}
-
 //=======================================================================
 //function : CDM_Document
 //purpose  : 
@@ -52,7 +46,6 @@ static CDM_PresentationDirectory& getPresentations() {
 
 CDM_Document::CDM_Document():
   myResourcesAreLoaded          (Standard_False),
-  myValidPresentation           (Standard_False),
   myVersion                     (1),
   myActualReferenceIdentifier   (0),
   myStorageVersion              (0),
@@ -229,11 +222,6 @@ Handle(CDM_Reference) CDM_Document::Reference
   return theReference;
 }
 
-static CDM_ListOfDocument& getListOfDocumentToUpdate() {
-  static CDM_ListOfDocument theListOfDocumentToUpdate;
-  return theListOfDocumentToUpdate;
-}
-
 //=======================================================================
 //function : IsInSession
 //purpose  : 
@@ -286,25 +274,23 @@ TCollection_ExtendedString CDM_Document::Name
 //function : UpdateFromDocuments
 //purpose  : 
 //=======================================================================
-
 void CDM_Document::UpdateFromDocuments(const Standard_Address aModifContext) const
 {
-  Standard_Boolean StartUpdateCycle=getListOfDocumentToUpdate().IsEmpty();
-  
+  CDM_ListOfDocument aListOfDocumentsToUpdate;
+  Standard_Boolean StartUpdateCycle = aListOfDocumentsToUpdate.IsEmpty();
   CDM_ListIteratorOfListOfReferences it(myFromReferences);
   for(; it.More() ; it.Next()) {
     Handle(CDM_Document) theFromDocument=it.Value()->FromDocument();
     CDM_ListIteratorOfListOfDocument itUpdate;
-
     for(; itUpdate.More(); itUpdate.Next()) {
       if(itUpdate.Value() == theFromDocument) break;
-      
+
       if(itUpdate.Value()->ShallowReferences(theFromDocument)) {
-	getListOfDocumentToUpdate().InsertBefore(theFromDocument,itUpdate);
+        aListOfDocumentsToUpdate.InsertBefore(theFromDocument,itUpdate);
 	break;
       }
     }
-    if(!itUpdate.More()) getListOfDocumentToUpdate().Append(theFromDocument);
+    if(!itUpdate.More()) aListOfDocumentsToUpdate.Append(theFromDocument);
     theFromDocument->Update(this,it.Value()->ReferenceIdentifier(),aModifContext);
   }
   
@@ -314,15 +300,15 @@ void CDM_Document::UpdateFromDocuments(const Standard_Address aModifContext) con
     Handle(CDM_Application) theApplication;
     TCollection_ExtendedString ErrorString;
 
-    while(!getListOfDocumentToUpdate().IsEmpty()) {
-      theDocumentToUpdate=getListOfDocumentToUpdate().First();
+    while(!aListOfDocumentsToUpdate.IsEmpty()) {
+      theDocumentToUpdate = aListOfDocumentsToUpdate.First();
       theApplication=theDocumentToUpdate->Application();
       ErrorString.Clear();
       theApplication->BeginOfUpdate(theDocumentToUpdate);
       theApplication->EndOfUpdate (theDocumentToUpdate,
                                    theDocumentToUpdate->Update(ErrorString),
                                    ErrorString);
-      getListOfDocumentToUpdate().RemoveFirst();
+      aListOfDocumentsToUpdate.RemoveFirst();
     }
   }
 }
@@ -519,104 +505,6 @@ Standard_ExtString CDM_Document::Comment() const
   return myComments(1).ToExtString();
 }
 
-//=======================================================================
-//function : Presentation
-//purpose  : 
-//=======================================================================
-
-Standard_ExtString CDM_Document::Presentation()
-{
-  if(!myValidPresentation) ComputePresentation();
-  return myPresentation.ToExtString();
-}
-
-//=======================================================================
-//function : UnvalidPresentation
-//purpose  : 
-//=======================================================================
-
-void CDM_Document::UnvalidPresentation()
-{
-  if(myValidPresentation) {
-    getPresentations().UnBind(myPresentation);
-    myValidPresentation=Standard_False;
-  }
-}
-
-//=======================================================================
-//function : ComputePresentation
-//purpose  : 
-//=======================================================================
-
-void CDM_Document::ComputePresentation()
-{
-  TCollection_ExtendedString presentation("");
-  static Standard_Integer theUnnamedDocuments(0);
-  static CDM_NamesDirectory theNames;
-
-  if(!myMetaData.IsNull()) {
-    presentation += myMetaData->Name();
-    if(!theNames.IsBound(presentation)) theNames.Bind(presentation,0);
-    Standard_Integer range = theNames(presentation);
-    range += 1;
-    theNames(presentation) = range;
-    if(range != 1) {
-      presentation += "<";
-      presentation += range;
-      presentation += ">";
-    }
-  }
-  else {
-    presentation = "Document_";
-    presentation += ++theUnnamedDocuments;
-  }
-  
-  if(getPresentations().IsBound(presentation)) {
-    TCollection_ExtendedString Test = presentation;
-    Test += "!";
-    Standard_Integer Count=0;
-    while (getPresentations().IsBound(Test)) {
-      Count++;
-      Test = presentation; Test+= "!"; Test+= Count;
-    }
-    presentation = Test;
-  }
-  
-  
-  myPresentation = TCollection_ExtendedString(presentation);
-  myValidPresentation = Standard_True;
-  getPresentations().Bind(presentation,this);
-}
-
-//=======================================================================
-//function : FindFromPresentation
-//purpose  : 
-//=======================================================================
-
-Handle(CDM_Document) CDM_Document::FindFromPresentation
-                                (const TCollection_ExtendedString& aPresentation)
-{
-  TCollection_ExtendedString x(aPresentation);
-  if(!getPresentations().IsBound(x)) {
-    Standard_SStream aMsg;
-    aMsg <<"No document having this presentation: " << x << " does exist."
-         << std::endl << (char)0;
-    throw Standard_NoSuchObject(aMsg.str().c_str());
-  }
-  return getPresentations()(x);
-}
-
-//=======================================================================
-//function : FindPresentation
-//purpose  : 
-//=======================================================================
-
-Standard_Boolean CDM_Document::FindPresentation
-                                (const TCollection_ExtendedString& aPresentation)
-{
-  return getPresentations().IsBound(aPresentation);
-}
-
 //=======================================================================
 //function : IsStored
 //purpose  : 
@@ -649,7 +537,7 @@ void CDM_Document::SetMetaData(const Handle(CDM_MetaData)& aMetaData)
     aMetaData->SetDocument(this);
 
 // Update the document refencing this MetaData:
-    CDM_DataMapIteratorOfMetaDataLookUpTable it(CDM_MetaData::LookUpTable());
+    CDM_DataMapIteratorOfMetaDataLookUpTable it(*CDM_MetaData::LookUpTable());
     for(;it.More();it.Next()) {
       const Handle(CDM_MetaData)& theMetaData=it.Value();
       if(theMetaData != aMetaData && theMetaData->IsRetrieved()) {
@@ -660,11 +548,8 @@ void CDM_Document::SetMetaData(const Handle(CDM_MetaData)& aMetaData)
       }
     }
     if(!myMetaData.IsNull()) {
-      if(myMetaData->Name() != aMetaData->Name()) UnvalidPresentation();
       myMetaData->UnsetDocument();
     }
-    else
-      UnvalidPresentation();
   }
 
   myStorageVersion = Modifications();
@@ -684,7 +569,6 @@ void CDM_Document::UnsetIsStored()
 {
   if(!myMetaData.IsNull()) { 
     myMetaData->UnsetDocument();
-//    myMetaData.Nullify();
   }
 }
 
@@ -791,7 +675,7 @@ TCollection_ExtendedString CDM_Document::RequestedName()
     if(!myMetaData.IsNull())
       myRequestedName=myMetaData->Name();
     else
-      myRequestedName=Presentation();
+      myRequestedName="Document_";
   }
   myRequestedNameIsDefined=Standard_True;
   return myRequestedName;
@@ -912,7 +796,6 @@ void CDM_Document::Close()
   RemoveAllReferences();
   UnsetIsStored();
   myApplication.Nullify();
-  UnvalidPresentation();
 
 }
 
@@ -1299,8 +1182,6 @@ void CDM_Document::DumpJson (Standard_OStream& theOStream, Standard_Integer theD
     const TCollection_ExtendedString& aComment = aCommentIt.Value();
     OCCT_DUMP_FIELD_VALUE_STRING (theOStream, aComment)
   }
-  OCCT_DUMP_FIELD_VALUE_STRING (theOStream, myPresentation)
-  OCCT_DUMP_FIELD_VALUE_NUMERICAL (theOStream, myValidPresentation)
 
   for (CDM_ListOfReferences::Iterator aFromReferenceIt (myFromReferences); aFromReferenceIt.More(); aFromReferenceIt.Next())
   {
diff --git a/src/CDM/CDM_Document.hxx b/src/CDM/CDM_Document.hxx
index fcecd90b49..31506813a7 100644
--- a/src/CDM/CDM_Document.hxx
+++ b/src/CDM/CDM_Document.hxx
@@ -25,6 +25,7 @@
 #include <TColStd_SequenceOfExtendedString.hxx>
 #include <TCollection_ExtendedString.hxx>
 #include <Standard_OStream.hxx>
+#include <CDM_ListOfDocument.hxx>
 
 class CDM_MetaData;
 class CDM_Application;
@@ -216,21 +217,6 @@ public:
   //! the comment is an empty string.
   Standard_EXPORT Standard_ExtString Comment() const;
   
-  //! Returns an alphanumeric string identifying this document
-  //! in a unique manner in the current process. The presentation
-  //! may change when the document is stored.
-  //! Tries to get the 'FileFormat`.Presentation resource
-  //! This item is used to give a default presentation
-  //! to the document.
-  Standard_EXPORT Standard_ExtString Presentation();
-  
-  //! returns the document having the given alphanumeric presentation.
-  Standard_EXPORT static Handle(CDM_Document) FindFromPresentation (const TCollection_ExtendedString& aPresentation);
-  
-  //! indicates whether a document having the given presentation
-  //! does exist.
-  Standard_EXPORT static Standard_Boolean FindPresentation (const TCollection_ExtendedString& aPresentation);
-  
   Standard_EXPORT Standard_Boolean IsStored() const;
   
   //! returns  the value of  the modification counter at the
@@ -374,10 +360,6 @@ private:
   //! the manager returned by  this method will be
   //! used to search for the following resource items.
   Standard_EXPORT Handle(Resource_Manager) StorageResource();
-
-  Standard_EXPORT void ComputePresentation();
-  
-  Standard_EXPORT void UnvalidPresentation();
   
   Standard_EXPORT void AddToReference (const Handle(CDM_Reference)& aReference);
   
@@ -385,9 +367,8 @@ private:
   
   Standard_EXPORT void RemoveFromReference (const Standard_Integer aReferenceIdentifier);
 
+
   TColStd_SequenceOfExtendedString myComments;
-  TCollection_ExtendedString myPresentation;
-  Standard_Boolean myValidPresentation;
   CDM_ListOfReferences myFromReferences;
   CDM_ListOfReferences myToReferences;
   Standard_Integer myVersion;
@@ -407,7 +388,6 @@ private:
   Standard_Boolean myDescriptionWasFound;
   Handle(CDM_Application) myApplication;
   Standard_Integer myStorageFormatVersion;
-
 };
 
 
diff --git a/src/CDM/CDM_MetaData.cxx b/src/CDM/CDM_MetaData.cxx
index 4f9db10ff2..e6629304a8 100644
--- a/src/CDM/CDM_MetaData.cxx
+++ b/src/CDM/CDM_MetaData.cxx
@@ -20,17 +20,16 @@
 #include <CDM_MetaData.hxx>
 #include <CDM_MetaDataLookUpTable.hxx>
 #include <CDM_Reference.hxx>
+#include <CDF_Session.hxx>
 #include <Standard_Dump.hxx>
+#include <CDF_Application.hxx>
 #include <Standard_NoSuchObject.hxx>
 #include <Standard_Type.hxx>
 #include <TCollection_ExtendedString.hxx>
+#include <OSD_Thread.hxx>
 
 IMPLEMENT_STANDARD_RTTIEXT(CDM_MetaData,Standard_Transient)
 
-static CDM_MetaDataLookUpTable& getLookUpTable(){
-  static CDM_MetaDataLookUpTable theLookUpTable;
-  return theLookUpTable;
-}
 CDM_MetaData::CDM_MetaData(const TCollection_ExtendedString& aFolder, const TCollection_ExtendedString& aName, const TCollection_ExtendedString& aPath,const TCollection_ExtendedString& aFileName,const Standard_Boolean ReadOnly):
 myIsRetrieved(Standard_False),
 myDocument(NULL),
@@ -75,12 +74,14 @@ Handle(CDM_MetaData) CDM_MetaData::LookUp(const TCollection_ExtendedString& aFol
   Handle(CDM_MetaData) theMetaData;
   TCollection_ExtendedString aConventionalPath=aPath;
   aConventionalPath.ChangeAll('\\','/');
-  if(!getLookUpTable().IsBound(aConventionalPath)) {
+  CDM_MetaDataLookUpTable* aLookUpTable = LookUpTable();
+  if (!aLookUpTable) return theMetaData;
+  if(!aLookUpTable->IsBound(aConventionalPath)) {
     theMetaData = new CDM_MetaData(aFolder,aName,aPath,aFileName,ReadOnly);
-    getLookUpTable().Bind(aConventionalPath,theMetaData);
+    aLookUpTable->Bind(aConventionalPath, theMetaData);
   }
   else
-    theMetaData = getLookUpTable()(aConventionalPath);
+    theMetaData = aLookUpTable->Find(aConventionalPath);
   
   return theMetaData;
 }
@@ -88,12 +89,14 @@ Handle(CDM_MetaData) CDM_MetaData::LookUp(const TCollection_ExtendedString& aFol
   Handle(CDM_MetaData) theMetaData;
   TCollection_ExtendedString aConventionalPath=aPath;
   aConventionalPath.ChangeAll('\\','/');
-  if(!getLookUpTable().IsBound(aConventionalPath)) {
+  CDM_MetaDataLookUpTable* aLookUpTable = LookUpTable();
+  if (!aLookUpTable) return theMetaData;
+  if(!aLookUpTable->IsBound(aConventionalPath)) {
     theMetaData = new CDM_MetaData(aFolder,aName,aPath,aVersion,aFileName,ReadOnly);
-    getLookUpTable().Bind(aConventionalPath,theMetaData);
+    aLookUpTable->Bind(aConventionalPath,theMetaData);
   }
   else
-    theMetaData = getLookUpTable()(aConventionalPath);
+    theMetaData = aLookUpTable->Find(aConventionalPath);
   
   return theMetaData;
 }
@@ -130,8 +133,14 @@ Standard_OStream& CDM_MetaData::Print(Standard_OStream& anOStream) const {
 Standard_OStream& CDM_MetaData::operator << (Standard_OStream& anOStream) {
   return Print(anOStream);
 }
-const CDM_MetaDataLookUpTable& CDM_MetaData::LookUpTable() {
-  return getLookUpTable();
+
+CDM_MetaDataLookUpTable* CDM_MetaData::LookUpTable() {
+  Handle(CDF_Session) aSession = CDF_Session::Create();
+  Handle(CDF_Application) anApp;
+  CDM_MetaDataLookUpTable* pLookUpTable(NULL);
+  if (aSession->FindApplication(OSD_Thread::Current(), anApp))
+    return anApp->MetaDataLookUpTable();
+  return pLookUpTable;
 }
 Standard_Integer CDM_MetaData::DocumentVersion(const Handle(CDM_Application)& anApplication) {
   if(myDocumentVersion==0) myDocumentVersion=anApplication->DocumentVersion(this);
diff --git a/src/CDM/CDM_MetaData.hxx b/src/CDM/CDM_MetaData.hxx
index 76c783494e..ca991716fc 100644
--- a/src/CDM/CDM_MetaData.hxx
+++ b/src/CDM/CDM_MetaData.hxx
@@ -115,7 +115,7 @@ private:
   
   Standard_EXPORT void SetDocument (const Handle(CDM_Document)& aDocument);
   
-  Standard_EXPORT static const CDM_MetaDataLookUpTable& LookUpTable();
+  Standard_EXPORT static CDM_MetaDataLookUpTable* LookUpTable();
   
   Standard_EXPORT Standard_Integer DocumentVersion (const Handle(CDM_Application)& anApplication);
 
diff --git a/src/CDM/CDM_MetaDataLookUpTable.hxx b/src/CDM/CDM_MetaDataLookUpTable.hxx
index e94d1b1457..b925bad765 100644
--- a/src/CDM/CDM_MetaDataLookUpTable.hxx
+++ b/src/CDM/CDM_MetaDataLookUpTable.hxx
@@ -19,7 +19,7 @@
 
 #include <TCollection_ExtendedString.hxx>
 #include <NCollection_DataMap.hxx>
-
+class CDM_MetaData;
 
 typedef NCollection_DataMap<TCollection_ExtendedString,Handle(CDM_MetaData),TCollection_ExtendedString> CDM_MetaDataLookUpTable;
 typedef NCollection_DataMap<TCollection_ExtendedString,Handle(CDM_MetaData),TCollection_ExtendedString>::Iterator CDM_DataMapIteratorOfMetaDataLookUpTable;
diff --git a/src/CDM/FILES b/src/CDM/FILES
index e1e386807f..46b7bc4094 100644
--- a/src/CDM/FILES
+++ b/src/CDM/FILES
@@ -2,7 +2,6 @@ CDM_Application.cxx
 CDM_Application.hxx
 CDM_CanCloseStatus.hxx
 CDM_DataMapIteratorOfMetaDataLookUpTable.hxx
-CDM_DataMapIteratorOfPresentationDirectory.hxx
 CDM_Document.cxx
 CDM_Document.hxx
 CDM_DocumentHasher.hxx
@@ -17,7 +16,7 @@ CDM_MetaData.cxx
 CDM_MetaData.hxx
 CDM_MetaDataLookUpTable.hxx
 CDM_NamesDirectory.hxx
-CDM_PresentationDirectory.hxx
+CDM_ApplicationDirectory.hxx
 CDM_Reference.cxx
 CDM_Reference.hxx
 CDM_ReferenceIterator.cxx
diff --git a/src/PCDM/PCDM_ReadWriter.cxx b/src/PCDM/PCDM_ReadWriter.cxx
index f3cc807c5b..cce1c5c378 100644
--- a/src/PCDM/PCDM_ReadWriter.cxx
+++ b/src/PCDM/PCDM_ReadWriter.cxx
@@ -74,8 +74,7 @@ void PCDM_ReadWriter::Open (const Handle(Storage_BaseDriver)&   aDriver,
 Handle(PCDM_ReadWriter) PCDM_ReadWriter::Reader
                                            (const TCollection_ExtendedString&)
 {
-  static Handle(PCDM_ReadWriter_1) theReader=new PCDM_ReadWriter_1;
-  return theReader;
+  return (new PCDM_ReadWriter_1);
 }
 
 //=======================================================================
@@ -85,8 +84,7 @@ Handle(PCDM_ReadWriter) PCDM_ReadWriter::Reader
 
 Handle(PCDM_ReadWriter) PCDM_ReadWriter::Writer ()
 {
-  static Handle(PCDM_ReadWriter_1) theWriter=new PCDM_ReadWriter_1;
-  return theWriter;
+  return (new PCDM_ReadWriter_1);
 }
  
 //=======================================================================
@@ -120,9 +118,7 @@ TCollection_ExtendedString PCDM_ReadWriter::FileFormat
   if (PCDM::FileDriverType (theFileName, theFileDriver) == PCDM_TOFD_Unknown)
     return ::TryXmlDriverType (theFileName);
 
-  static Standard_Boolean theFileIsOpen;
-  theFileIsOpen=Standard_False;
-
+  Standard_Boolean theFileIsOpen(Standard_False);
   try {
     OCC_CATCH_SIGNALS
     
diff --git a/src/PCDM/PCDM_ReadWriter_1.cxx b/src/PCDM/PCDM_ReadWriter_1.cxx
index 500f485f2c..723e45e090 100644
--- a/src/PCDM/PCDM_ReadWriter_1.cxx
+++ b/src/PCDM/PCDM_ReadWriter_1.cxx
@@ -226,18 +226,14 @@ void PCDM_ReadWriter_1::WriteVersion(const Handle(Storage_Data)& aData, const Ha
 
 Standard_Integer PCDM_ReadWriter_1::ReadReferenceCounter(const TCollection_ExtendedString& aFileName, const Handle(Message_Messenger)& theMsgDriver) const {
 
-  static Standard_Integer theReferencesCounter ;
-  theReferencesCounter=0;
-  static Standard_Integer i ;
-
+  Standard_Integer theReferencesCounter(0) ;
+  Standard_Integer i ;
   Handle(Storage_BaseDriver) theFileDriver;
   TCollection_AsciiString aFileNameU(aFileName);
   if(PCDM::FileDriverType(aFileNameU, theFileDriver) == PCDM_TOFD_Unknown)
     return theReferencesCounter;
   
-  static Standard_Boolean theFileIsOpen ;
-  theFileIsOpen=Standard_False;
-
+  Standard_Boolean theFileIsOpen(Standard_False);
   try {
     OCC_CATCH_SIGNALS
     PCDM_ReadWriter::Open(theFileDriver,aFileName,Storage_VSRead);
@@ -342,7 +338,7 @@ void PCDM_ReadWriter_1::ReadUserInfo(const TCollection_ExtendedString& aFileName
                                      TColStd_SequenceOfExtendedString& theUserInfo,
                                      const Handle(Message_Messenger)&)
 {
-  static Standard_Integer i ;
+  Standard_Integer i ;
   Handle(Storage_BaseDriver) theFileDriver;
   TCollection_AsciiString aFileNameU(aFileName);
   if(PCDM::FileDriverType(aFileNameU, theFileDriver) == PCDM_TOFD_Unknown)
@@ -377,16 +373,13 @@ void PCDM_ReadWriter_1::ReadUserInfo(const TCollection_ExtendedString& aFileName
 
 Standard_Integer PCDM_ReadWriter_1::ReadDocumentVersion(const TCollection_ExtendedString& aFileName, const Handle(Message_Messenger)& theMsgDriver) const {
 
-  static Standard_Integer theVersion ;
-  theVersion=-1;
-
+  Standard_Integer theVersion(-1);
   Handle(Storage_BaseDriver) theFileDriver;
   TCollection_AsciiString aFileNameU(aFileName);
   if(PCDM::FileDriverType(aFileNameU, theFileDriver) == PCDM_TOFD_Unknown)
     return theVersion;
 
-  static Standard_Boolean theFileIsOpen ;
-  theFileIsOpen =Standard_False;
+  Standard_Boolean theFileIsOpen(Standard_False);
 
   try {
     OCC_CATCH_SIGNALS
@@ -397,7 +390,7 @@ Standard_Integer PCDM_ReadWriter_1::ReadDocumentVersion(const TCollection_Extend
     hd.Read (theFileDriver);
     const TColStd_SequenceOfAsciiString &refUserInfo = hd.UserInfo();
 
-    static Standard_Integer i ;
+    Standard_Integer i ;
     for ( i =1; i<=  refUserInfo.Length() ; i++) {
       if(refUserInfo(i).Search(MODIFICATION_COUNTER) != -1) {
 	try { OCC_CATCH_SIGNALS theVersion=refUserInfo(i).Token(" ",2).IntegerValue();}
diff --git a/src/PCDM/PCDM_StorageDriver.cxx b/src/PCDM/PCDM_StorageDriver.cxx
index 8aeb79d6be..ad5dd7a092 100644
--- a/src/PCDM/PCDM_StorageDriver.cxx
+++ b/src/PCDM/PCDM_StorageDriver.cxx
@@ -50,8 +50,7 @@ void PCDM_StorageDriver::Write (const Handle(CDM_Document)& aDocument,
 
   Handle(Storage_Data) theData = new Storage_Data;
 
-  static Standard_Boolean Failure;
-  Failure=Standard_False;
+  Standard_Boolean Failure(Standard_False);
   Standard_SStream aMsg; aMsg << "error during Make:";
   PCDM_SequenceOfDocument thePersistentDocuments;
   {
diff --git a/src/QABugs/QABugs_18.cxx b/src/QABugs/QABugs_18.cxx
index 5876f9a870..3b0224f36c 100644
--- a/src/QABugs/QABugs_18.cxx
+++ b/src/QABugs/QABugs_18.cxx
@@ -29,7 +29,6 @@
 #include <TDocStd_Application.hxx>
 #include <TDocStd_Document.hxx>
 #include <DDocStd.hxx>
-#include <CDF.hxx>
 
 #include <Resource_Manager.hxx>
 #include <TopoDS_Wire.hxx>
diff --git a/src/QABugs/QABugs_20.cxx b/src/QABugs/QABugs_20.cxx
index bc4f8d8d92..4dba1d03c4 100644
--- a/src/QABugs/QABugs_20.cxx
+++ b/src/QABugs/QABugs_20.cxx
@@ -2976,6 +2976,217 @@ static Standard_Integer OCC30391(Draw_Interpretor& theDI,
   return 0;
 }
 
+#include <Standard_Mutex.hxx>
+#include <NCollection_Sequence.hxx>
+#include <BinLDrivers.hxx>
+#include <BinDrivers.hxx>
+#include <XmlLDrivers.hxx>
+#include <XmlDrivers.hxx>
+#include <StdLDrivers.hxx>
+#include <StdDrivers.hxx>
+#include <TDF_ChildIterator.hxx>
+#include <TDocStd_PathParser.hxx>
+#include <OSD.hxx>
+#include <OSD_Thread.hxx>
+#include <OSD_Environment.hxx>
+typedef NCollection_Sequence <TCollection_AsciiString> SequenceOfDocNames;
+
+typedef struct
+{
+  Standard_ThreadId ID;
+  int iThread;  
+  TCollection_AsciiString inFile[3];
+  TCollection_AsciiString outFile[2];
+  bool finished;
+  int* res;
+} Args;
+
+static void printMsg(const char* msg)
+{
+  printf("%s\n", msg);
+}
+
+static Standard_Integer nbREP(50);
+
+void* threadFunction(void* theArgs)
+{
+  Args* args = (Args*)theArgs;
+  try
+  {
+    if(args->inFile[0].IsEmpty())
+    {
+      *(args->res) = -1;
+      return args->res;
+    }
+
+    Handle(TDocStd_Application) anApp = new TDocStd_Application();
+    OCC_CATCH_SIGNALS;
+    BinLDrivers::DefineFormat(anApp);
+    BinDrivers::DefineFormat(anApp);
+    XmlLDrivers::DefineFormat(anApp);
+    XmlDrivers::DefineFormat(anApp);
+    StdLDrivers::DefineFormat(anApp);
+    StdDrivers::DefineFormat(anApp);
+
+    for (int aFileIndex = 0; aFileIndex < 3; aFileIndex++)
+    {
+      TCollection_AsciiString aDocName = args->inFile[aFileIndex];
+      Handle(TDocStd_Document) aDoc;
+      for (int i = 1; i <= nbREP; i++) {
+
+        PCDM_ReaderStatus aStatus = anApp->Open(aDocName, aDoc);
+        if (aStatus != PCDM_RS_OK) {
+          args->finished = true;
+          *(args->res) = -1;
+          return args->res;
+        }
+        else {
+          TDF_Label aLabel = aDoc->Main();
+          TDF_ChildIterator anIt(aLabel, Standard_True);
+          for (; anIt.More(); anIt.Next()) {
+            const TDF_Label& aLab = anIt.Value();
+            Handle(TDataStd_AsciiString) anAtt;
+            aLab.FindAttribute(TDataStd_AsciiString::GetID(), anAtt);
+            if (!anAtt.IsNull()) {
+              TCollection_AsciiString aStr = anAtt->Get();
+              if (aStr.IsEqual(aDocName)) {
+                *(args->res) = (int)aLab.Tag();
+                break;
+              }
+            }
+          }
+
+          if (aFileIndex != 2) {
+            TCollection_AsciiString anOutDocName = args->outFile[aFileIndex];
+            anApp->SaveAs(aDoc, anOutDocName);
+          }
+          anApp->Close(aDoc);
+        }
+      }
+    }
+    args->finished = true;
+    anApp->RemoveFromSession();
+  }
+  catch (...)
+  {
+    args->finished = true;
+    *(args->res) = -1;
+    return args->res;
+  }
+  args->finished = true;
+  return args->res;
+}
+
+int getNumCores()
+{
+#ifdef WIN32
+  SYSTEM_INFO sysinfo;
+  GetSystemInfo(&sysinfo);
+  return sysinfo.dwNumberOfProcessors;
+#elif MACOS
+  int nm[2];
+  size_t len = 4;
+  uint32_t count;
+
+  nm[0] = CTL_HW; nm[1] = HW_AVAILCPU;
+  sysctl(nm, 2, &count, &len, NULL, 0);
+
+  if (count < 1) {
+    nm[1] = HW_NCPU;
+    sysctl(nm, 2, &count, &len, NULL, 0);
+    if (count < 1) { count = 1; }
+  }
+  return count;
+#else
+  return sysconf(_SC_NPROCESSORS_ONLN);
+#endif
+}
+
+//=======================================================================
+//function : OCC29195
+//purpose  : 
+//=======================================================================
+static Standard_Integer OCC29195(Draw_Interpretor&, Standard_Integer theArgC, const char** theArgV)
+{
+  if (theArgC < 2)
+  {
+    std::cout << "\nOCC29195 [nbRep] doc1.cbf doc1.xml doc1.std outDoc1.cbf outDoc1.xml doc2.cbf doc2.xml doc2.std outDoc2.cbf outDoc2.xml ...], where:";
+    std::cout << "\nnbRep - number repetitions of a thread function (by default - 50)";
+    std::cout << "\ndocN - names (5 in each group) of OCAF documents names (3 input files, 2 output)\n" << std::endl;
+    return 1;
+  }
+  int iThread(0), nbThreads(0), off(0);
+  if (TCollection_AsciiString(theArgV[1]).IsIntegerValue())
+  {
+    nbREP = TCollection_AsciiString(theArgV[1]).IntegerValue();
+    off = 1;
+  }
+  if (theArgC - off - 1 < 5 || (theArgC - off - 1) % 5 != 0 )
+  {
+    printMsg("TEST is FAILED: number of arguments is invalid\n");
+    return 0;
+  }
+  Standard_Integer aNbFiles = (theArgC - off - 1) / 5;
+  nbThreads = getNumCores();
+  if (aNbFiles < nbThreads)
+  {
+    nbThreads = aNbFiles;
+  }
+  // Allocate data
+  Args* args = new Args[nbThreads];
+  OSD_Thread* threads = new OSD_Thread[nbThreads];
+  while (iThread < nbThreads)
+  {
+    if (iThread < aNbFiles)
+    {      
+      args[iThread].inFile[0] = theArgV[iThread * 5 + off + 1];
+      args[iThread].inFile[1] = theArgV[iThread * 5 + off + 2];
+      args[iThread].inFile[2] = theArgV[iThread * 5 + off + 3];
+      args[iThread].outFile[0] = theArgV[iThread * 5 + off + 4];
+      args[iThread].outFile[1] = theArgV[iThread * 5 + off + 5];
+    }
+    args[iThread].iThread = iThread;
+    args[iThread].ID = threads[iThread].GetId();
+    args[iThread].finished = false;
+    args[iThread].res = new int;
+    threads[iThread].SetFunction(&threadFunction);
+    iThread++;
+  }
+  for (iThread = 0; iThread < nbThreads; iThread++)
+  {
+    args[iThread].finished = false;
+    threads[iThread].Run((void*)&(args[iThread]));
+  }
+  // Sleep while the threads are run.
+  bool finished = false;
+  while (!finished)
+  {
+    OSD::MilliSecSleep(100);
+    finished = true;
+    for (iThread = 0; iThread < nbThreads && finished; iThread++)
+    {
+      finished = args[iThread].finished;
+    }
+  }
+  OSD_Environment anEnv("Result29195");
+  for (iThread = 0; iThread < nbThreads; iThread++)
+  {
+    if (*(args[iThread].res) == -1)
+    {
+      printMsg("OCC29195 is FAILED\n");
+      anEnv.SetValue("FAILED_ERR");
+      break;
+    }
+  }
+  if (iThread == nbThreads)
+  {
+    printMsg("OCC29195 is finished OK\n");
+    anEnv.SetValue("OK");
+  }
+  anEnv.Build();
+  return 0;
+}
+
 //=======================================================================
 //function : QAStartsWith string startstring
 //=======================================================================
@@ -3620,6 +3831,7 @@ void QABugs::Commands_20(Draw_Interpretor& theCommands) {
   theCommands.Add("OCC29807", "OCC29807 surface1 surface2 u1 v1 u2 v2", __FILE__, OCC29807, group);
   theCommands.Add("OCC29311", "OCC29311 shape counter nbiter: check performance of OBB calculation", __FILE__, OCC29311, group);
   theCommands.Add("OCC30391", "OCC30391 result face LenBeforeUfirst LenAfterUlast LenBeforeVfirst LenAfterVlast", __FILE__, OCC30391, group);
+  theCommands.Add("OCC29195", "OCC29195 [nbRep] doc1 [doc2 [doc3 [doc4]]]", __FILE__, OCC29195, group);
   theCommands.Add("OCC30435", "OCC30435 result curve inverse nbit", __FILE__, OCC30435, group);
   theCommands.Add("OCC30990", "OCC30990 surface", __FILE__, OCC30990, group);
 
diff --git a/src/TDocStd/TDocStd.cxx b/src/TDocStd/TDocStd.cxx
index 8905864862..04261f149d 100644
--- a/src/TDocStd/TDocStd.cxx
+++ b/src/TDocStd/TDocStd.cxx
@@ -22,7 +22,6 @@
 
 #include <TDocStd.hxx>
 
-#include <CDF.hxx>
 #include <OSD_Environment.hxx>
 #include <TDocStd_XLink.hxx>
 
diff --git a/src/TDocStd/TDocStd_Application.cxx b/src/TDocStd/TDocStd_Application.cxx
index 142c98ecf8..094e6ffae5 100644
--- a/src/TDocStd/TDocStd_Application.cxx
+++ b/src/TDocStd/TDocStd_Application.cxx
@@ -34,6 +34,7 @@
 #include <TDocStd_Document.hxx>
 #include <TDocStd_Owner.hxx>
 #include <TDocStd_PathParser.hxx>
+#include <OSD_Thread.hxx>
 
 #include<Message_ProgressSentry.hxx>
 
@@ -47,20 +48,9 @@ IMPLEMENT_STANDARD_RTTIEXT(TDocStd_Application,CDF_Application)
 TDocStd_Application::TDocStd_Application()
         : myIsDriverLoaded (Standard_True)
 {
-  myMessageDriver = CDM_Application::MessageDriver();
-  Handle(CDF_Session) S;
-  if (!CDF_Session::Exists()) S = new CDF_Session();
-  else S = CDF_Session::CurrentSession();
-  S->SetCurrentApplication(this);
-  try
-  {
-    OCC_CATCH_SIGNALS
-    S->LoadDriver();
-  }
-  catch (Plugin_Failure const&)
-  {
+  AddToSession();
+  if(myMetaDataDriver.IsNull())
     myIsDriverLoaded = Standard_False;
-  }
 }
 
 
@@ -73,15 +63,6 @@ Standard_Boolean TDocStd_Application::IsDriverLoaded() const
   return myIsDriverLoaded;
 }
 
-//=======================================================================
-//function : MessageDriver
-//purpose  :
-//=======================================================================
-Handle(Message_Messenger) TDocStd_Application::MessageDriver()
-{
-  return myMessageDriver;
-}
-
 //=======================================================================
 //function : Resources
 //purpose  :
@@ -179,8 +160,7 @@ Standard_Integer TDocStd_Application::NbDocuments() const
 {
   if (!CDF_Session::Exists())
     throw Standard_DomainError("TDocStd_Application::NbDocuments");
-  Handle(CDF_Session) S = CDF_Session::CurrentSession();
-  return S->Directory()->Length();
+  return this->myDirectory->Length();
 }
 
 //=======================================================================
@@ -192,8 +172,7 @@ void TDocStd_Application::GetDocument(const Standard_Integer index,Handle(TDocSt
 {
   if (!CDF_Session::Exists())
     throw Standard_DomainError("TDocStd_Application::NbDocuments");
-  Handle(CDF_Session) S = CDF_Session::CurrentSession();
-  CDF_DirectoryIterator it (S->Directory());
+  CDF_DirectoryIterator it (myDirectory);
   Standard_Integer current = 0;
   for (;it.MoreDocument();it.NextDocument()) {
     current++;
@@ -624,6 +603,19 @@ void TDocStd_Application::OnCommitTransaction (const Handle(TDocStd_Document)&)
   // nothing to do on this level
 }
 
+//
+void TDocStd_Application::AddToSession()
+{
+  Handle(CDF_Session) S = CDF_Session::Create();
+  S->AddApplication(this, OSD_Thread::Current());
+}
+
+Standard_Boolean TDocStd_Application::RemoveFromSession()
+{
+  Handle(CDF_Session) aSession = CDF_Session::Create();
+  return aSession->RemoveApplication(OSD_Thread::Current());
+}
+
 //=======================================================================
 //function : DumpJson
 //purpose  : 
diff --git a/src/TDocStd/TDocStd_Application.hxx b/src/TDocStd/TDocStd_Application.hxx
index d4f30810e1..c168113683 100644
--- a/src/TDocStd/TDocStd_Application.hxx
+++ b/src/TDocStd/TDocStd_Application.hxx
@@ -79,9 +79,6 @@ public:
   //! Check if meta data driver was successfully loaded
   //! by the application constructor
   Standard_EXPORT Standard_Boolean IsDriverLoaded() const;
-
-  //! Redefines message driver, by default outputs to std::cout.
-  Standard_EXPORT virtual Handle(Message_Messenger) MessageDriver() Standard_OVERRIDE;
   
   //! Returns resource manager defining supported persistent formats.
   //!
@@ -286,12 +283,20 @@ public:
   //! Dumps the content of me into the stream
   Standard_EXPORT void DumpJson (Standard_OStream& theOStream, Standard_Integer theDepth = -1) const;
 
-  DEFINE_STANDARD_RTTIEXT(TDocStd_Application,CDF_Application)
+  //! Remove this application from the current session
+  Standard_EXPORT Standard_Boolean RemoveFromSession();
+
+  DEFINE_STANDARD_RTTIEXT(TDocStd_Application, CDF_Application)
 
 protected:
-  Handle(Message_Messenger) myMessageDriver;
+
   Handle(Resource_Manager) myResources;
   Standard_Boolean myIsDriverLoaded;
+
+private:
+
+  //! Add this application to the current session (register in internal container)
+  void AddToSession();
 };
 
 #endif // _TDocStd_Application_HeaderFile
diff --git a/src/TKQADraw/EXTERNLIB b/src/TKQADraw/EXTERNLIB
index 816969b002..cfaa6d7997 100755
--- a/src/TKQADraw/EXTERNLIB
+++ b/src/TKQADraw/EXTERNLIB
@@ -34,6 +34,11 @@ TKXSDRAW
 TKSTL
 TKXml
 TKTObj
+TKXmlL
+TKBin
+TKBinL
+TKStd
+TKStdL
 CSF_gdi32
 CSF_advapi32
 CSF_user32
diff --git a/src/TObj/TObj_Application.cxx b/src/TObj/TObj_Application.cxx
index 35588bbe21..7e889a44c6 100644
--- a/src/TObj/TObj_Application.cxx
+++ b/src/TObj/TObj_Application.cxx
@@ -25,7 +25,8 @@
 #include <Message_Msg.hxx>
 #include <Message_MsgFile.hxx>
 #include <Resource_Manager.hxx>
-
+#include <CDF_Session.hxx>
+#include <OSD_Thread.hxx>
 #include <stdio.h>
 
 #include "TObj_TObj_msg.pxx"
@@ -36,11 +37,13 @@ IMPLEMENT_STANDARD_RTTIEXT(TObj_Application,TDocStd_Application)
 //function : GetInstance
 //purpose  :
 //=======================================================================
-
 Handle(TObj_Application) TObj_Application::GetInstance()
 {
-  static Handle(TObj_Application) anInstance = new TObj_Application;
-  return anInstance;
+  Handle(CDF_Session) aSession = CDF_Session::Create();
+  Handle(CDF_Application) anApp;
+  if (aSession->FindApplication(OSD_Thread::Current(), anApp))
+    return Handle(TObj_Application)::DownCast(anApp);
+  return new TObj_Application;
 }
 
 //=======================================================================
diff --git a/src/TObjDRAW/TObjDRAW.cxx b/src/TObjDRAW/TObjDRAW.cxx
index 209d824ca9..30ceb8b25d 100644
--- a/src/TObjDRAW/TObjDRAW.cxx
+++ b/src/TObjDRAW/TObjDRAW.cxx
@@ -510,12 +510,11 @@ void TObjDRAW::Init(Draw_Interpretor& di)
 void TObjDRAW::Factory(Draw_Interpretor& theDI)
 {
   // Initialize TObj OCAF formats
-  Handle(TDocStd_Application) anApp = DDocStd::GetApplication();
+  Handle(TDocStd_Application) anApp = TObj_Application::GetInstance();//DDocStd::GetApplication();
   BinTObjDrivers::DefineFormat(anApp);
   XmlTObjDrivers::DefineFormat(anApp);
 
   // define formats for TObj specific application
-  anApp = TObj_Application::GetInstance();
   BinTObjDrivers::DefineFormat(anApp);
   XmlTObjDrivers::DefineFormat(anApp);
 
diff --git a/src/XmlLDrivers/XmlLDrivers_DocumentStorageDriver.hxx b/src/XmlLDrivers/XmlLDrivers_DocumentStorageDriver.hxx
index aa5d7b0482..48a3c28eef 100644
--- a/src/XmlLDrivers/XmlLDrivers_DocumentStorageDriver.hxx
+++ b/src/XmlLDrivers/XmlLDrivers_DocumentStorageDriver.hxx
@@ -26,6 +26,7 @@
 #include <Standard_Boolean.hxx>
 #include <XmlObjMgt_Element.hxx>
 #include <Standard_Integer.hxx>
+
 class XmlMDF_ADriverTable;
 class TCollection_ExtendedString;
 class CDM_Document;
@@ -81,8 +82,7 @@ protected:
                                  const Handle(Message_ProgressIndicator)& theProgress = NULL);
 
   Handle(XmlMDF_ADriverTable) myDrivers;
-  XmlObjMgt_SRelocationTable myRelocTable;
-
+  XmlObjMgt_SRelocationTable  myRelocTable;
 
 private:
 
diff --git a/tests/bugs/caf/bug29195_1 b/tests/bugs/caf/bug29195_1
new file mode 100644
index 0000000000..31d7f9c256
--- /dev/null
+++ b/tests/bugs/caf/bug29195_1
@@ -0,0 +1,39 @@
+pload QAcommands
+##set imagedir [pwd]
+
+set aFile1 [locate_data_file bug29195_1.cbf]
+set aFile2 [locate_data_file bug29195_2.cbf]
+set aFile3 [locate_data_file bug29195_3.cbf]
+set aFile4 [locate_data_file bug29195_4.cbf]
+set aFile5 [locate_data_file bug29195_1.xml]
+set aFile6 [locate_data_file bug29195_2.xml]
+set aFile7 [locate_data_file bug29195_3.xml]
+set aFile8 [locate_data_file bug29195_4.xml]
+set aFile9 [locate_data_file bug29195_1.std]
+set aFile10 [locate_data_file bug29195_2.std]
+set aFile11 [locate_data_file bug29195_3.std]
+set aFile12 [locate_data_file bug29195_4.std]
+
+
+set aNew1 ${imagedir}/new_bug29195_1.cbf
+set aNew2 ${imagedir}/new_bug29195_2.cbf
+set aNew3 ${imagedir}/new_bug29195_3.cbf
+set aNew4 ${imagedir}/new_bug29195_4.cbf
+set aNew5 ${imagedir}/new_bug29195_1.xml
+set aNew6 ${imagedir}/new_bug29195_2.xml
+set aNew7 ${imagedir}/new_bug29195_3.xml
+set aNew8 ${imagedir}/new_bug29195_4.xml
+
+OCC29195 50 $aFile1 $aFile5 $aFile9 ${aNew1} ${aNew5} $aFile2 $aFile6 $aFile10 ${aNew2} ${aNew6} $aFile3 $aFile7 $aFile11 ${aNew3} ${aNew7} $aFile4 $aFile8 $aFile12 ${aNew4} ${aNew8}
+set RES [dgetenv Result29195]
+
+if { [file exists ${aNew1}] } {file delete ${aNew1}}
+if { [file exists ${aNew2}] } {file delete ${aNew2}}
+if { [file exists ${aNew3}] } {file delete ${aNew3}}
+if { [file exists ${aNew4}] } {file delete ${aNew4}}
+if { [file exists ${aNew5}] } {file delete ${aNew5}}
+if { [file exists ${aNew6}] } {file delete ${aNew6}}
+if { [file exists ${aNew7}] } {file delete ${aNew7}}
+if { [file exists ${aNew8}] } {file delete ${aNew8}}
+
+puts "OCC29195 is $RES"
diff --git a/tools/DFBrowser/DFBrowser_Window.cxx b/tools/DFBrowser/DFBrowser_Window.cxx
index f0415e5eca..a4e25b4b10 100644
--- a/tools/DFBrowser/DFBrowser_Window.cxx
+++ b/tools/DFBrowser/DFBrowser_Window.cxx
@@ -53,7 +53,7 @@
 #include <OSD_Directory.hxx>
 #include <OSD_Environment.hxx>
 #include <OSD_Protection.hxx>
-
+#include <OSD_Thread.hxx>
 #include <inspector/View_Displayer.hxx>
 #include <inspector/View_ToolBar.hxx>
 #include <inspector/View_Viewer.hxx>
@@ -64,6 +64,7 @@
 #include <inspector/ViewControl_Tools.hxx>
 
 #include <Standard_WarningsDisable.hxx>
+#include <Standard_ThreadId.hxx>
 #include <QAction>
 #include <QApplication>
 #include <QComboBox>
@@ -440,8 +441,12 @@ void DFBrowser_Window::Init (const NCollection_List<Handle(Standard_Transient)>&
   }
   else
   {
-    if (anApplication.IsNull() && CDF_Session::Exists())
-      anApplication = Handle(TDocStd_Application)::DownCast (CDF_Session::CurrentSession()->CurrentApplication());
+    if (anApplication.IsNull() && CDF_Session::Exists()) {
+      Standard_ThreadId anID = OSD_Thread::Current();
+      Handle(CDF_Application) anApp;
+      CDF_Session::CurrentSession()->FindApplication(anID, anApp);
+      anApplication = Handle(TDocStd_Application)::DownCast (anApp);
+    }
   }
 
   myModule = new DFBrowser_Module();
@@ -504,7 +509,10 @@ void DFBrowser_Window::OpenFile (const TCollection_AsciiString& theFileName)
     Handle(CDF_Session) aSession = CDF_Session::CurrentSession();
     if (!aSession.IsNull())
     {
-      anApplication = Handle(TDocStd_Application)::DownCast (CDF_Session::CurrentSession()->CurrentApplication());
+      Standard_ThreadId anID = OSD_Thread::Current();
+      Handle(CDF_Application) anApp;
+      CDF_Session::CurrentSession()->FindApplication(anID, anApp);
+      anApplication = Handle(TDocStd_Application)::DownCast (anApp);
       if (!anApplication.IsNull())
       {
         for (int aDocId = 1, aNbDocuments = anApplication->NbDocuments(); aDocId <= aNbDocuments; aDocId++)
diff --git a/tools/DFBrowserPane/DFBrowserPane_TDocStdOwner.cxx b/tools/DFBrowserPane/DFBrowserPane_TDocStdOwner.cxx
index 61f48d334f..88d57a7c5e 100644
--- a/tools/DFBrowserPane/DFBrowserPane_TDocStdOwner.cxx
+++ b/tools/DFBrowserPane/DFBrowserPane_TDocStdOwner.cxx
@@ -77,7 +77,7 @@ void DFBrowserPane_TDocStdOwner::GetValues (const Handle(TDF_Attribute)& theAttr
 
   // CDM_Document methods
   theValues << "Comments" << convertToString (aComments)
-            << "Presentation" << DFBrowserPane_Tools::ToString (aDocument->Presentation())
+   //         << "Presentation" << DFBrowserPane_Tools::ToString (aDocument->Presentation())
             << "IsStored" << DFBrowserPane_Tools::BoolToStr (aDocument->IsStored())
             << "StorageVersion" << QString::number (aDocument->StorageVersion())
             << "Folder" << (aDocument->IsStored() ? DFBrowserPane_Tools::ToString (aDocument->Folder()) : "")