diff --git a/hurricane/src/hurricane/DBo.cpp b/hurricane/src/hurricane/DBo.cpp
index 257c40e5..66238588 100644
--- a/hurricane/src/hurricane/DBo.cpp
+++ b/hurricane/src/hurricane/DBo.cpp
@@ -157,7 +157,7 @@ namespace Hurricane {
   }
 
 
-  DBo::~DBo () throw(Error)
+  DBo::~DBo ()
   {
     if (_idCount) --_idCount;
     else {
diff --git a/hurricane/src/hurricane/Entity.cpp b/hurricane/src/hurricane/Entity.cpp
index 38bf0a24..ffe49007 100644
--- a/hurricane/src/hurricane/Entity.cpp
+++ b/hurricane/src/hurricane/Entity.cpp
@@ -38,7 +38,7 @@ namespace Hurricane {
   { }
 
 
-  Entity::~Entity() throw(Error)
+  Entity::~Entity()
   { }
   
 
diff --git a/hurricane/src/hurricane/Go.cpp b/hurricane/src/hurricane/Go.cpp
index 913b170e..f7615dea 100644
--- a/hurricane/src/hurricane/Go.cpp
+++ b/hurricane/src/hurricane/Go.cpp
@@ -38,7 +38,7 @@ Go::Go()
 {
 }
 
-Go::~Go() throw(Error)
+Go::~Go()
 { }
 
 bool Go::autoMaterializationIsDisabled()
diff --git a/hurricane/src/hurricane/Hook.cpp b/hurricane/src/hurricane/Hook.cpp
index afa4890b..cadca6ae 100644
--- a/hurricane/src/hurricane/Hook.cpp
+++ b/hurricane/src/hurricane/Hook.cpp
@@ -196,8 +196,8 @@ Hook::Hook()
 {
 }
 
-Hook::~Hook() throw(Error)
-// ***********************
+Hook::~Hook()
+// **********
 {
     if (_nextHook != this)
         throw Error("Abnormal deletion of hook : always attached");
diff --git a/hurricane/src/hurricane/hurricane/DBo.h b/hurricane/src/hurricane/hurricane/DBo.h
index 39051717..c84d89e6 100644
--- a/hurricane/src/hurricane/hurricane/DBo.h
+++ b/hurricane/src/hurricane/hurricane/DBo.h
@@ -1,6 +1,6 @@
 // -*- C++ -*-
 //
-// Copyright (c) BULL S.A. 2000-2018, All Rights Reserved
+// Copyright (c) BULL S.A. 2000-2021, All Rights Reserved
 //
 // This file is part of Hurricane.
 //
@@ -29,13 +29,11 @@
 // +-----------------------------------------------------------------+
 
 
-#ifndef  HURRICANE_DBO_H
-#define  HURRICANE_DBO_H
-
-#include  "hurricane/Error.h"
-#include  "hurricane/DBos.h"
-#include  "hurricane/Name.h"
-#include  "hurricane/Properties.h"
+#pragma  once
+#include "hurricane/Error.h"
+#include "hurricane/DBos.h"
+#include "hurricane/Name.h"
+#include "hurricane/Properties.h"
 
 
 namespace Hurricane {
@@ -83,7 +81,7 @@ namespace Hurricane {
               void               toJsonSignature     ( JsonWriter* ) const;
     protected:                   
                                  DBo                 ();
-      virtual                   ~DBo                 () throw(Error);
+      virtual                   ~DBo                 ();
       virtual void               _postCreate         ();
       virtual void               _preDestroy         ();
     private:                                         
@@ -136,5 +134,3 @@ namespace Hurricane {
 } // Hurricane namespace.
 
 INSPECTOR_P_SUPPORT(Hurricane::DBo);
-
-#endif // HURRICANE_DBO_H
diff --git a/hurricane/src/hurricane/hurricane/Entity.h b/hurricane/src/hurricane/hurricane/Entity.h
index 3316a36b..a2d2553d 100644
--- a/hurricane/src/hurricane/hurricane/Entity.h
+++ b/hurricane/src/hurricane/hurricane/Entity.h
@@ -17,9 +17,7 @@
 // not, see <http://www.gnu.org/licenses/>.
 // ****************************************************************************************************
 
-#ifndef HURRICANE_ENTITY
-#define HURRICANE_ENTITY
-
+#pragma  once
 #include <functional>
 #include "hurricane/DBo.h"
 #include "hurricane/Entities.h"
@@ -48,7 +46,7 @@ namespace Hurricane {
               Quark*        _getQuark           ( SharedPath* sharedPath = NULL ) const;
     protected:                                  
                             Entity              ();
-      virtual              ~Entity              () throw(Error);
+      virtual              ~Entity              ();
       virtual void          _postCreate         ();
       virtual void          _preDestroy         ();
   };
@@ -91,9 +89,6 @@ namespace Hurricane {
 
 INSPECTOR_P_SUPPORT(Hurricane::Entity);
 
-
-#endif // HURRICANE_ENTITY
-
 // ****************************************************************************************************
 // Copyright (c) BULL S.A. 2000-2018, All Rights Reserved
 // ****************************************************************************************************
diff --git a/hurricane/src/hurricane/hurricane/Go.h b/hurricane/src/hurricane/hurricane/Go.h
index fc253a44..b0112e04 100644
--- a/hurricane/src/hurricane/hurricane/Go.h
+++ b/hurricane/src/hurricane/hurricane/Go.h
@@ -17,9 +17,7 @@
 // not, see <http://www.gnu.org/licenses/>.
 // ****************************************************************************************************
 
-#ifndef HURRICANE_GO
-#define HURRICANE_GO
-
+#pragma  once
 #include "hurricane/Entity.h"
 #include "hurricane/Gos.h"
 #include "hurricane/Transformation.h"
@@ -56,7 +54,7 @@ class Go : public Entity {
 // ************
 
     protected: Go();
-    protected: virtual ~Go() throw(Error);
+    protected: virtual ~Go();
 
 // Predicates
 // **********
@@ -101,9 +99,6 @@ class Go : public Entity {
 INSPECTOR_P_SUPPORT(Hurricane::Go);
 
 
-#endif // HURRICANE_GO
-
-
 // ****************************************************************************************************
 // Copyright (c) BULL S.A. 2000-2018, All Rights Reserved
 // ****************************************************************************************************
diff --git a/hurricane/src/hurricane/hurricane/Hook.h b/hurricane/src/hurricane/hurricane/Hook.h
index ebafd20d..e5520f63 100644
--- a/hurricane/src/hurricane/hurricane/Hook.h
+++ b/hurricane/src/hurricane/hurricane/Hook.h
@@ -17,9 +17,7 @@
 // not, see <http://www.gnu.org/licenses/>.
 // ****************************************************************************************************
 
-#ifndef HURRICANE_HOOK
-#define HURRICANE_HOOK
-
+#pragma  once
 #include "hurricane/Error.h"
 #include "hurricane/Hooks.h"
 
@@ -54,7 +52,7 @@ class Hook {
 // Destructor
 // **********
 
-  protected: virtual ~Hook() throw(Error);
+  protected: virtual ~Hook();
 
 // Operators
 // *********
@@ -115,9 +113,6 @@ class Hook {
 INSPECTOR_P_SUPPORT(Hurricane::Hook);
 
 
-#endif // HURRICANE_HOOK
-
-
 // ****************************************************************************************************
 // Copyright (c) BULL S.A. 2000-2018, All Rights Reserved
 // ****************************************************************************************************
diff --git a/hurricane/src/hurricane/hurricane/IntrusiveMap.h b/hurricane/src/hurricane/hurricane/IntrusiveMap.h
index 7ca44572..0b750c3d 100644
--- a/hurricane/src/hurricane/hurricane/IntrusiveMap.h
+++ b/hurricane/src/hurricane/hurricane/IntrusiveMap.h
@@ -1,7 +1,7 @@
 // ****************************************************************************************************
 // File: ./hurricane/IntrusiveMap.h
 // Authors: R. Escassut
-// Copyright (c) BULL S.A. 2000-2018, All Rights Reserved
+// Copyright (c) BULL S.A. 2000-2021, All Rights Reserved
 //
 // This file is part of Hurricane.
 //
@@ -17,9 +17,7 @@
 // not, see <http://www.gnu.org/licenses/>.
 // ****************************************************************************************************
 
-#ifndef HURRICANE_INTRUSIVE_MAP
-#define HURRICANE_INTRUSIVE_MAP
-
+#pragma  once
 #include <cstring>
 #include <algorithm>
 
@@ -988,7 +986,6 @@ inline void  jsonWrite ( JsonWriter* w, const std::string& key, Hurricane::Intru
   for ( Element* element : intrusiveMap->getElements() ) jsonWrite( w, element );
   w->endArray();
 }
-#endif // HURRICANE_INTRUSIVE_MAP
 
 
 // ****************************************************************************************************
diff --git a/hurricane/src/hurricane/hurricane/IntrusiveSet.h b/hurricane/src/hurricane/hurricane/IntrusiveSet.h
index 4da23905..7e52b20b 100644
--- a/hurricane/src/hurricane/hurricane/IntrusiveSet.h
+++ b/hurricane/src/hurricane/hurricane/IntrusiveSet.h
@@ -17,9 +17,7 @@
 // not, see <http://www.gnu.org/licenses/>.
 // ****************************************************************************************************
 
-#ifndef HURRICANE_INTRUSIVE_SET
-#define HURRICANE_INTRUSIVE_SET
-
+#pragma  once
 #include <cstring>
 #include <algorithm>
 
@@ -497,9 +495,6 @@ inline Hurricane::Record* getRecord ( Hurricane::IntrusiveSet<Type>& intrusiveSe
 { return intrusiveSet._getRecord(); }
 
 
-#endif // HURRICANE_INTRUSIVE_SET
-
-
 // ****************************************************************************************************
 // Copyright (c) BULL S.A. 2000-2018, All Rights Reserved
 // ****************************************************************************************************
diff --git a/hurricane/src/hurricane/hurricane/Observer.h b/hurricane/src/hurricane/hurricane/Observer.h
index bb573d6b..04d8a025 100644
--- a/hurricane/src/hurricane/hurricane/Observer.h
+++ b/hurricane/src/hurricane/hurricane/Observer.h
@@ -14,9 +14,7 @@
 // +-----------------------------------------------------------------+
 
 
-#ifndef  HURRICANE_OBSERVER_H
-#define  HURRICANE_OBSERVER_H
-
+#pragma  once
 #include <vector>
 #include <array>
 #include "hurricane/Error.h"
@@ -168,5 +166,3 @@ namespace Hurricane {
 
 
 } // Hurricane namespace.
-
-#endif
diff --git a/hurricane/src/hurricane/hurricane/Property.h b/hurricane/src/hurricane/hurricane/Property.h
index 6a6797ad..b48d010e 100644
--- a/hurricane/src/hurricane/hurricane/Property.h
+++ b/hurricane/src/hurricane/hurricane/Property.h
@@ -1,6 +1,6 @@
 // -*- C++ -*-
 //
-// Copyright (c) BULL S.A. 2000-2018, All Rights Reserved
+// Copyright (c) BULL S.A. 2000-2021, All Rights Reserved
 //
 // This file is part of Hurricane.
 //
@@ -29,13 +29,11 @@
 // +-----------------------------------------------------------------+
 
 
-#ifndef  HURRICANE_PROPERTY_H
-#define  HURRICANE_PROPERTY_H
-
-#include  "hurricane/Name.h"
-#include  "hurricane/Properties.h"
-#include  "hurricane/DBo.h"
-#include  "hurricane/Error.h"
+#pragma  once
+#include "hurricane/Name.h"
+#include "hurricane/Properties.h"
+#include "hurricane/DBo.h"
+#include "hurricane/Error.h"
 
 
 namespace Hurricane {
@@ -597,6 +595,3 @@ namespace Hurricane {
 
 
 INSPECTOR_P_SUPPORT(Hurricane::Property);
-
-
-#endif // HURRICANE_PROPERTY_H
diff --git a/hurricane/src/hurricane/hurricane/Timer.h b/hurricane/src/hurricane/hurricane/Timer.h
index 52d81ff1..93daeae9 100644
--- a/hurricane/src/hurricane/hurricane/Timer.h
+++ b/hurricane/src/hurricane/hurricane/Timer.h
@@ -34,23 +34,21 @@
 //! author="Igor Markov 06/22/97 "      
 // freely inspired from abktimer from UCLApack .... just no windows.
 
-#ifndef  HURRICANE_TIMER_H
-#define  HURRICANE_TIMER_H
+#pragma  once
+#include <sys/types.h>
+#include <sys/time.h>
+#include <unistd.h>
+#include <time.h>
+#include <math.h>
 
-#include  <sys/types.h>
-#include  <sys/time.h>
-#include  <unistd.h>
-#include  <time.h>
-#include  <math.h>
-
-#include  <sys/resource.h>
+#include <sys/resource.h>
 #if defined(sun)
 extern "C" int  getrusage ( int who, struct rusage *rusage );
 #elif defined(linux)
 #endif      
 
-#include  "hurricane/Error.h"
-#include  "hurricane/Slot.h"
+#include "hurricane/Error.h"
+#include "hurricane/Slot.h"
 
 
 namespace Hurricane {
@@ -182,5 +180,3 @@ namespace Hurricane {
 
 GETSTRING_VALUE_SUPPORT(Hurricane::Timer);
 IOSTREAM_VALUE_SUPPORT(Hurricane::Timer);
-
-#endif  // HURRICANE_TIMER_H
diff --git a/vlsisapd/src/bookshelf/src/vlsisapd/bookshelf/Exception.h b/vlsisapd/src/bookshelf/src/vlsisapd/bookshelf/Exception.h
index 737f244d..ed9a5e5f 100644
--- a/vlsisapd/src/bookshelf/src/vlsisapd/bookshelf/Exception.h
+++ b/vlsisapd/src/bookshelf/src/vlsisapd/bookshelf/Exception.h
@@ -35,12 +35,12 @@ namespace Bookshelf {
 
   class Exception : public std::exception {
     public:
-               Exception ( const std::string& ) throw();
-               Exception ( const char* format, ... ) throw();
-               Exception ( const Exception& ) throw();
-      virtual ~Exception () throw();
+               Exception ( const std::string& );
+               Exception ( const char* format, ... );
+               Exception ( const Exception& );
+      virtual ~Exception ();
     public:
-      virtual const char* what       () const throw ();
+      virtual const char* what       () const;
     private:
       static std::string  _addHeader ( const char* );
     private:
diff --git a/vlsisapd/src/dtr/src/vlsisapd/dtr/DTRException.h b/vlsisapd/src/dtr/src/vlsisapd/dtr/DTRException.h
index ea556f13..3f1a70ed 100644
--- a/vlsisapd/src/dtr/src/vlsisapd/dtr/DTRException.h
+++ b/vlsisapd/src/dtr/src/vlsisapd/dtr/DTRException.h
@@ -27,17 +27,17 @@ namespace DTR {
 
   class DTRException {
 	public:
-      inline                     DTRException (const std::string& what) throw();
-      inline virtual            ~DTRException () throw();
-      inline virtual const char* what         () const throw();
+      inline                     DTRException (const std::string& what);
+      inline virtual            ~DTRException ();
+      inline virtual const char* what         () const;
     private:
       std::string  _what;
   };
 
 
-  inline             DTRException::DTRException  ( const std::string& what ) throw() : _what(what) {}
-  inline             DTRException::~DTRException () throw() {}
-  inline const char* DTRException::what          () const throw() { return _what.c_str(); }
+  inline             DTRException::DTRException  ( const std::string& what ) : _what(what) {}
+  inline             DTRException::~DTRException () {}
+  inline const char* DTRException::what          () const { return _what.c_str(); }
 
 
 } // DTR namespace.
diff --git a/vlsisapd/src/spice/src/vlsisapd/spice/SpiceException.h b/vlsisapd/src/spice/src/vlsisapd/spice/SpiceException.h
index 9c5a0687..38d31945 100644
--- a/vlsisapd/src/spice/src/vlsisapd/spice/SpiceException.h
+++ b/vlsisapd/src/spice/src/vlsisapd/spice/SpiceException.h
@@ -7,9 +7,9 @@
 namespace SPICE {
 class SpiceException {
 	public:
-        SpiceException(const std::string& what) throw() : _what(what) {}
-        virtual const char* what() const throw() { return _what.c_str(); }
-        virtual ~SpiceException() throw() {}
+        SpiceException(const std::string& what) : _what(what) {}
+        virtual const char* what() const { return _what.c_str(); }
+        virtual ~SpiceException() {}
         
     private:
         std::string _what;