diff --git a/Common/Context.h b/Common/Context.h
index 721763b4765c9a007987d90197969d7ff2c4d7c1..58ebfbae8238582238a519720bb6e0b0b18d9641 100644
--- a/Common/Context.h
+++ b/Common/Context.h
@@ -26,7 +26,7 @@
 // integer. Don't use 'LITTLE_ENDIAN': Apple defines it in its system
 // headers.
 
-#if defined(_BIG_ENDIAN)
+#if defined(HAVE_BIG_ENDIAN)
 #  define PACK_COLOR(R,G,B,A)   ( (R)<<24 | (G)<<16 | (B)<<8 | (A) )
 #  define UNPACK_RED(X)         ( ( (X) >> 24 ) & 0xff )
 #  define UNPACK_GREEN(X)       ( ( (X) >> 16 ) & 0xff )
diff --git a/Parallel/ParUtil.cpp b/Parallel/ParUtil.cpp
index aa4f244fa32de8c05954f8253b1a0b0c5fc72f62..08dde95bd7cbb7f2294faae356f4425db0ef577b 100644
--- a/Parallel/ParUtil.cpp
+++ b/Parallel/ParUtil.cpp
@@ -1,4 +1,4 @@
-// $Id: ParUtil.cpp,v 1.9 2004-02-07 01:40:23 geuzaine Exp $
+// $Id: ParUtil.cpp,v 1.10 2004-03-05 01:21:06 geuzaine Exp $
 //
 // Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 //
@@ -23,7 +23,7 @@
 #include <stdlib.h>
 #include <string.h>
 #include "ParUtil.h"
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
 #include "mpi.h"
 #else
 #include <sys/time.h>
@@ -49,7 +49,7 @@ ParUtil::ParUtil()
 
 void ParUtil::init(int &argc, char **&argv)
 {
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   int namelen;
   char name[1024];
   MPI_Init(&argc, &argv);
@@ -66,7 +66,7 @@ void ParUtil::init(int &argc, char **&argv)
 
 double ParUtil::wTime() const
 {
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   return MPI_Wtime();
 #else
   struct timeval tp;
@@ -84,7 +84,7 @@ double ParUtil::wTime() const
 
 void ParUtil::processorName(char *name) const
 {
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   strcpy(name, procName);
 #else
   strcpy(name, "localhost");
@@ -93,7 +93,7 @@ void ParUtil::processorName(char *name) const
 
 void ParUtil::Abort()
 {
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   MPI_Abort(MPI_COMM_WORLD, 1);
 #else
   abort();
@@ -102,7 +102,7 @@ void ParUtil::Abort()
 
 void ParUtil::Exit()
 {
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   MPI_Finalize();
 #else
   exit(0);
@@ -111,7 +111,7 @@ void ParUtil::Exit()
 
 void ParUtil::Barrier(int line, const char *fn)
 {
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   MPI_Barrier(MPI_COMM_WORLD);
 #endif
 }
diff --git a/Parallel/ParUtil.h b/Parallel/ParUtil.h
index 1db667b9e19aa4623d9d575b680e914b0cf1fa5a..15424c717cb1040e4f9016f244274230dbcd94ef 100644
--- a/Parallel/ParUtil.h
+++ b/Parallel/ParUtil.h
@@ -45,7 +45,7 @@ public:
   void processorName(char *name) const;
   /// abort a calculation
   void Abort();
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   inline int rank() { return myrank; }
   inline int size() { return mysize; }
   inline int master() { return myrank==0; }
@@ -60,7 +60,7 @@ public:
 private:
   static ParUtil *instance;
   char *procName;
-#ifdef PARALLEL
+#ifdef HAVE_PARALLEL
   int myrank;
   int mysize;
 #endif
diff --git a/Plugin/Plugin.cpp b/Plugin/Plugin.cpp
index 47f7573e214c4929d43441ae9ead34f6c9b8d60a..1675248b7ff00ed2831442ab16bacd3121b7ca3c 100644
--- a/Plugin/Plugin.cpp
+++ b/Plugin/Plugin.cpp
@@ -1,4 +1,4 @@
-// $Id: Plugin.cpp,v 1.46 2004-02-07 01:40:30 geuzaine Exp $
+// $Id: Plugin.cpp,v 1.47 2004-03-05 01:21:06 geuzaine Exp $
 //
 // Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 //
@@ -19,7 +19,7 @@
 // 
 // Please report all bugs and problems to <gmsh@geuz.org>.
 
-#if !defined(_NO_DLL)
+#if !defined(HAVE_NO_DLL)
 #include <dlfcn.h>
 #endif
 
@@ -185,7 +185,7 @@ void GMSH_PluginManager::registerDefaultPlugins()
 
 void GMSH_PluginManager::addPlugin(char *dirName, char *pluginName)
 {
-#if defined(_NO_DLL) || !defined(HAVE_FLTK)
+#if defined(HAVE_NO_DLL) || !defined(HAVE_FLTK)
   Msg(WARNING, "No dynamic plugin loading on this platform");
   return;
 #else
diff --git a/configure b/configure
index 70941b43be524960d6e4a0725e28c783bc2fe51e..9bde675907e7b32e98eda5216d60501020a4938b 100755
--- a/configure
+++ b/configure
@@ -3709,7 +3709,7 @@ echo "$as_me: error: Could not find GSL, aborting." >&2;}
 fi
 
 if test "x$enable_parallel" = "xyes"; then
-  FLAGS="-DPARALLEL ${FLAGS}"
+  FLAGS="-DHAVE_PARALLEL ${FLAGS}"
 fi
 
 if test "x$enable_system_menubar" = "xyes"; then
@@ -3736,7 +3736,7 @@ case "$UNAME" in
     ;;
 
   Darwin*)
-    FLAGS="-D_NO_DLL ${FLAGS}"
+    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
     if test "x$enable_gui" = "xno"; then
       GMSH_LIBS="${GMSH_LIBS} -framework ApplicationServices"
     fi
@@ -3744,7 +3744,7 @@ case "$UNAME" in
     ;;
 
   AIX*)
-    FLAGS="-D_BSD -D_NO_DLL ${FLAGS}"
+    FLAGS="-D_BSD -DHAVE_NO_DLL ${FLAGS}"
     ;;
 
   IRIX*)
@@ -3763,12 +3763,12 @@ case "$UNAME" in
     ;;
 
   SunOS*)
-    FLAGS="-D_NO_DLL ${FLAGS}"
+    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
     GMSH_LIBS="${GMSH_LIBS} -lsocket -lnsl -ldl"
     ;;
 
   HP-UX*)
-    FLAGS="-D_NO_DLL ${FLAGS}"
+    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
     ;;
 
 esac
@@ -3962,7 +3962,7 @@ echo "$as_me:$LINENO: result: $ac_cv_c_bigendian" >&5
 echo "${ECHO_T}$ac_cv_c_bigendian" >&6
 case $ac_cv_c_bigendian in
   yes)
-    FLAGS="-D_BIG_ENDIAN ${FLAGS}" ;;
+    FLAGS="-DHAVE_BIG_ENDIAN ${FLAGS}" ;;
   no)
      ;;
   *)
diff --git a/configure.in b/configure.in
index 188b7c0bc05bd0847d9dcdb6ef53ec6d81c2af73..1909dc0b429ce5175cc43688f668db0b644f9f2b 100644
--- a/configure.in
+++ b/configure.in
@@ -1,4 +1,4 @@
-dnl $Id: configure.in,v 1.49 2004-02-07 01:40:16 geuzaine Exp $
+dnl $Id: configure.in,v 1.50 2004-03-05 01:21:06 geuzaine Exp $
 dnl
 dnl Copyright (C) 1997-2004 C. Geuzaine, J.-F. Remacle
 dnl
@@ -288,7 +288,7 @@ fi
 
 dnl Check if we should build the parallel version
 if test "x$enable_parallel" = "xyes"; then
-  FLAGS="-DPARALLEL ${FLAGS}"
+  FLAGS="-DHAVE_PARALLEL ${FLAGS}"
 fi
 
 dnl Check if we should enable the system menu bar on MacOS X
@@ -319,7 +319,7 @@ case "$UNAME" in
     ;;
 
   Darwin*)
-    FLAGS="-D_NO_DLL ${FLAGS}"
+    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
     if test "x$enable_gui" = "xno"; then
       GMSH_LIBS="${GMSH_LIBS} -framework ApplicationServices"
     fi
@@ -327,7 +327,7 @@ case "$UNAME" in
     ;;
 
   AIX*)
-    FLAGS="-D_BSD -D_NO_DLL ${FLAGS}"
+    FLAGS="-D_BSD -DHAVE_NO_DLL ${FLAGS}"
     ;;
 
   IRIX*)
@@ -346,18 +346,18 @@ case "$UNAME" in
     ;;
 
   SunOS*)
-    FLAGS="-D_NO_DLL ${FLAGS}"
+    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
     GMSH_LIBS="${GMSH_LIBS} -lsocket -lnsl -ldl"
     ;;
 
   HP-UX*)
-    FLAGS="-D_NO_DLL ${FLAGS}"
+    FLAGS="-DHAVE_NO_DLL ${FLAGS}"
     ;;
 
 esac
 
 dnl Is the machine big or little endian?
-AC_C_BIGENDIAN(FLAGS="-D_BIG_ENDIAN ${FLAGS}")
+AC_C_BIGENDIAN(FLAGS="-DHAVE_BIG_ENDIAN ${FLAGS}")
 
 dnl Check for header files
 AC_HEADER_STDC