diff --git a/src/AIModel/AIFlightPlan.cxx b/src/AIModel/AIFlightPlan.cxx
index f18f0a346..abb49de43 100644
--- a/src/AIModel/AIFlightPlan.cxx
+++ b/src/AIModel/AIFlightPlan.cxx
@@ -26,9 +26,6 @@
 #include <simgear/math/sg_geodesy.hxx>
 #include <simgear/structure/exception.hxx>
 #include <simgear/constants.h>
-#ifdef __BORLANDC__
-#  define exception c_exception
-#endif
 #include <simgear/props/props.hxx>
 #include <Main/globals.hxx>
 #include <Main/fg_props.hxx>
diff --git a/src/ATCDCL/ATCVoice.hxx b/src/ATCDCL/ATCVoice.hxx
index 0bc501c20..3185cc023 100644
--- a/src/ATCDCL/ATCVoice.hxx
+++ b/src/ATCDCL/ATCVoice.hxx
@@ -23,12 +23,7 @@
 
 #include <simgear/compiler.h>
 
-#if defined( SG_HAVE_STD_INCLUDES ) || defined( __BORLANDC__ ) || (__APPLE__)
 #  include <fstream>
-#else
-#  include <fstream.h>
-#endif
-
 #include <map>
 #include <list>
 #include <string>
diff --git a/src/ATCDCL/approach.hxx b/src/ATCDCL/approach.hxx
index ad6bea6a2..9ea32b9c0 100644
--- a/src/ATCDCL/approach.hxx
+++ b/src/ATCDCL/approach.hxx
@@ -33,15 +33,7 @@
 
 #include <Main/fg_props.hxx>
 
-#ifdef SG_HAVE_STD_INCLUDES
 #  include <iosfwd>
-#elif defined( SG_HAVE_NATIVE_SGI_COMPILERS )
-#  include <iostream.h>
-#elif defined( __BORLANDC__ )
-#  include <iostream>
-#else
-#  include <istream.h>
-#endif
 
 #include "ATC.hxx"
 #include "transmission.hxx"
diff --git a/src/ATCDCL/atis.hxx b/src/ATCDCL/atis.hxx
index c4c28e2d4..60335e185 100644
--- a/src/ATCDCL/atis.hxx
+++ b/src/ATCDCL/atis.hxx
@@ -32,13 +32,7 @@
 #include <simgear/magvar/magvar.hxx>
 #include <simgear/timing/sg_time.hxx>
 
-#ifdef SG_HAVE_STD_INCLUDES
 #  include <iosfwd>
-#elif defined( __BORLANDC__ ) || (__APPLE__)
-#  include <iostream>
-#else
-#  include <istream.h>
-#endif
 
 #include "ATC.hxx"
 
diff --git a/src/ATCDCL/transmission.hxx b/src/ATCDCL/transmission.hxx
index 8318d5a3b..c8ee2ce10 100644
--- a/src/ATCDCL/transmission.hxx
+++ b/src/ATCDCL/transmission.hxx
@@ -34,17 +34,7 @@
 
 #include <Main/fg_props.hxx>
 
-#ifdef SG_HAVE_STD_INCLUDES
 #  include <istream>
-#include <iomanip>
-#elif defined( SG_HAVE_NATIVE_SGI_COMPILERS )
-#  include <iostream.h>
-#elif defined( __BORLANDC__ )
-#  include <iostream>
-#else
-#  include <istream.h>
-#include <iomanip.h>
-#endif
 
 #include "ATC.hxx"
 
diff --git a/src/Cockpit/hud.cxx b/src/Cockpit/hud.cxx
index 564b536dc..703dbbc5f 100644
--- a/src/Cockpit/hud.cxx
+++ b/src/Cockpit/hud.cxx
@@ -34,12 +34,7 @@
 #  include <windows.h>
 #endif
 
-#ifdef __BORLANDC__
-#  define exception c_exception
-#endif
-
 #include <math.h>
-
 #include <stdlib.h>
 #include <stdio.h>              // char related functions
 #include <string.h>             // strcmp()
diff --git a/src/FDM/Balloon.cxx b/src/FDM/Balloon.cxx
index 7ff92a6fc..b56e6cf8b 100644
--- a/src/FDM/Balloon.cxx
+++ b/src/FDM/Balloon.cxx
@@ -43,10 +43,6 @@ HISTORY
 
 #include <simgear/compiler.h>
 
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
-
 #include STL_STRING
 
 #include <simgear/constants.h>
diff --git a/src/FDM/JSBSim/JSBSim.cxx b/src/FDM/JSBSim/JSBSim.cxx
index a6b1d7e0f..667a54b5d 100644
--- a/src/FDM/JSBSim/JSBSim.cxx
+++ b/src/FDM/JSBSim/JSBSim.cxx
@@ -28,9 +28,6 @@
 #include <simgear/compiler.h>
 
 #include <stdio.h>    //    size_t
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
 
 #include STL_STRING
 
diff --git a/src/FDM/JSBSim/input_output/FGfdmSocket.cpp b/src/FDM/JSBSim/input_output/FGfdmSocket.cpp
index 7d2178433..1c390696f 100644
--- a/src/FDM/JSBSim/input_output/FGfdmSocket.cpp
+++ b/src/FDM/JSBSim/input_output/FGfdmSocket.cpp
@@ -55,7 +55,7 @@ FGfdmSocket::FGfdmSocket(string address, int port, int protocol)
   sckt = sckt_in = size = 0;
   connected = false;
 
-  #if defined(__BORLANDC__) || defined(_MSC_VER) || defined(__MINGW32__)
+  #if defined(_MSC_VER) || defined(__MINGW32__)
     WSADATA wsaData;
     int wsaReturnCode;
     wsaReturnCode = WSAStartup(MAKEWORD(1,1), &wsaData);
@@ -109,7 +109,7 @@ FGfdmSocket::FGfdmSocket(string address, int port)
   sckt = sckt_in = size = 0;
   connected = false;
 
-  #if defined(__BORLANDC__) || defined(_MSC_VER) || defined(__MINGW32__)
+  #if defined(_MSC_VER) || defined(__MINGW32__)
     WSADATA wsaData;
     int wsaReturnCode;
     wsaReturnCode = WSAStartup(MAKEWORD(1,1), &wsaData);
@@ -162,7 +162,7 @@ FGfdmSocket::FGfdmSocket(int port)
   connected = false;
   unsigned long NoBlock = true;
 
-  #if defined(__BORLANDC__) || defined(_MSC_VER) || defined(__MINGW32__)
+  #if defined(_MSC_VER) || defined(__MINGW32__)
     WSADATA wsaData;
     int wsaReturnCode;
     wsaReturnCode = WSAStartup(MAKEWORD(1,1), &wsaData);
@@ -180,7 +180,7 @@ FGfdmSocket::FGfdmSocket(int port)
     if (bind(sckt, (struct sockaddr*)&scktName, len) == 0) {   // successful
       cout << "Successfully bound to socket for input on port " << port << endl;
       if (listen(sckt, 5) >= 0) { // successful listen()
-        #if defined(__BORLANDC__) || defined(_MSC_VER) || defined(__MINGW32__)
+        #if defined(_MSC_VER) || defined(__MINGW32__)
           ioctlsocket(sckt, FIONBIO, &NoBlock);
           sckt_in = accept(sckt, (struct sockaddr*)&scktName, &len);
         #else
@@ -207,10 +207,6 @@ FGfdmSocket::~FGfdmSocket()
 {
   if (sckt) shutdown(sckt,2);
   if (sckt_in) shutdown(sckt_in,2);
-
-  #ifdef __BORLANDC__
-    WSACleanup();
-  #endif
   Debug(1);
 }
 
@@ -227,13 +223,13 @@ string FGfdmSocket::Receive(void)
                     // class attribute and pass as a reference?
 
   if (sckt_in <= 0) {
-    #if defined(__BORLANDC__) || defined(_MSC_VER) || defined(__MINGW32__)
+    #if defined(_MSC_VER) || defined(__MINGW32__)
       sckt_in = accept(sckt, (struct sockaddr*)&scktName, &len);
     #else
       sckt_in = accept(sckt, (struct sockaddr*)&scktName, (socklen_t*)&len);
     #endif
     if (sckt_in > 0) {
-      #if defined(__BORLANDC__) || defined(_MSC_VER) || defined(__MINGW32__)
+      #if defined(_MSC_VER) || defined(__MINGW32__)
          ioctlsocket(sckt_in, FIONBIO,&NoBlock);
       #else
          ioctl(sckt_in, FIONBIO, &NoBlock);
diff --git a/src/FDM/JSBSim/input_output/FGfdmSocket.h b/src/FDM/JSBSim/input_output/FGfdmSocket.h
index 59db72325..c8f139103 100644
--- a/src/FDM/JSBSim/input_output/FGfdmSocket.h
+++ b/src/FDM/JSBSim/input_output/FGfdmSocket.h
@@ -49,7 +49,7 @@ INCLUDES
 using std::cout;
 using std::endl;
 
-#if defined(__BORLANDC__) || defined(_MSC_VER) || defined(__MINGW32__)
+#if defined(_MSC_VER) || defined(__MINGW32__)
   #include <winsock.h>
   #include <io.h>
 #else
diff --git a/src/GUI/gui_funcs.cxx b/src/GUI/gui_funcs.cxx
index ac2e7d4b6..de40bda0e 100644
--- a/src/GUI/gui_funcs.cxx
+++ b/src/GUI/gui_funcs.cxx
@@ -32,10 +32,6 @@
 
 #include <simgear/compiler.h>
 
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
-
 #ifdef HAVE_WINDOWS_H
 #  include <windows.h>
 #endif
diff --git a/src/GUI/mouse.cxx b/src/GUI/mouse.cxx
index ec2c4a68f..c6abe3585 100644
--- a/src/GUI/mouse.cxx
+++ b/src/GUI/mouse.cxx
@@ -30,10 +30,6 @@
 
 #include <simgear/compiler.h>
 
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
-
 #ifdef HAVE_WINDOWS_H
 #  include <windows.h>
 #endif
diff --git a/src/Main/fg_init.cxx b/src/Main/fg_init.cxx
index fdac2e800..353818a78 100644
--- a/src/Main/fg_init.cxx
+++ b/src/Main/fg_init.cxx
@@ -25,11 +25,6 @@
 #  include <config.h>
 #endif
 
-// For BC 5.01 this must be included before OpenGL includes.
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
-
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>             // strcmp()
diff --git a/src/Main/main.cxx b/src/Main/main.cxx
index ba2483da0..56204bff1 100644
--- a/src/Main/main.cxx
+++ b/src/Main/main.cxx
@@ -32,10 +32,6 @@
 #  include <signal.h>
 #endif
 
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
-
 #ifdef HAVE_WINDOWS_H
 #  include <windows.h>
 #  include <float.h>
diff --git a/src/Navaids/fix.hxx b/src/Navaids/fix.hxx
index 2335be1fb..666966a82 100644
--- a/src/Navaids/fix.hxx
+++ b/src/Navaids/fix.hxx
@@ -32,13 +32,7 @@
 #include <simgear/compiler.h>
 #include <simgear/misc/sgstream.hxx>
 
-#ifdef SG_HAVE_STD_INCLUDES
 #  include <istream>
-#elif defined( __BORLANDC__ ) || (__APPLE__)
-#  include <iostream>
-#else
-#  include <istream.h>
-#endif
 
 #include STL_STRING
 
diff --git a/src/Navaids/navrecord.hxx b/src/Navaids/navrecord.hxx
index d5ab6ec0b..4767dbf45 100644
--- a/src/Navaids/navrecord.hxx
+++ b/src/Navaids/navrecord.hxx
@@ -35,13 +35,7 @@
 #include <simgear/structure/SGSharedPtr.hxx>
 #include <simgear/structure/SGReferenced.hxx>
 
-#ifdef SG_HAVE_STD_INCLUDES
 #  include <istream>
-#elif defined( __BORLANDC__ ) || (__APPLE__)
-#  include <iostream>
-#else
-#  include <istream.h>
-#endif
 
 #define FG_NAV_DEFAULT_RANGE 50 // nm
 #define FG_LOC_DEFAULT_RANGE 18 // nm
diff --git a/src/Sound/fg_fx.cxx b/src/Sound/fg_fx.cxx
index e1f7f4f23..b158c9051 100644
--- a/src/Sound/fg_fx.cxx
+++ b/src/Sound/fg_fx.cxx
@@ -31,9 +31,6 @@
 
 #include <simgear/debug/logstream.hxx>
 #include <simgear/structure/exception.hxx>
-#ifdef __BORLANDC__
-#  define exception c_exception
-#endif
 #include <simgear/misc/sg_path.hxx>
 #include <simgear/props/props.hxx>
 #include <simgear/sound/xmlsound.hxx>
diff --git a/src/Time/light.cxx b/src/Time/light.cxx
index debccf586..cea586809 100644
--- a/src/Time/light.cxx
+++ b/src/Time/light.cxx
@@ -34,10 +34,6 @@
 
 #include SG_GL_H
 
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  define exception c_exception
-#endif
-
 #ifdef SG_HAVE_STD_INCLUDES
 #  include <cmath>
 #else