diff --git a/nsprpub/build/autoconf/config.guess b/nsprpub/build/autoconf/config.guess
index 5ce66fdbac79..6d5281f08c1d 100755
--- a/nsprpub/build/autoconf/config.guess
+++ b/nsprpub/build/autoconf/config.guess
@@ -1194,11 +1194,13 @@ EOF
 	fi
 	echo ${UNAME_MACHINE}-unknown-plan9
 	exit 0 ;;
-    i?86:OS/2:*:*)
-	# If we were able to find `uname', then EMX Unix compatibility
-	# is probably installed.
-	echo ${UNAME_MACHINE}-pc-os2-emx
-	exit 0 ;;
+    *:OS/2:*:*)
+	if test "$VACPP" = "yes"; then
+		echo "i386-pc-os2_vacpp"
+	else
+		echo "i386-pc-os2_emx"
+	fi
+    exit 0;;
 esac
 
 #echo '(No uname command or uname output not recognized.)' 1>&2
diff --git a/nsprpub/build/autoconf/config.sub b/nsprpub/build/autoconf/config.sub
index 1e47930dcb37..3875de918f40 100755
--- a/nsprpub/build/autoconf/config.sub
+++ b/nsprpub/build/autoconf/config.sub
@@ -995,6 +995,10 @@ case $os in
 	-gnu/linux*)
 		os=`echo $os | sed -e 's|gnu/linux|linux-gnu|'`
 		;;
+	-os2_emx)
+		;;
+	-os2_vacpp)
+		;;
 	# First accept the basic system types.
 	# The portable systems comes first.
 	# Each alternative MUST END IN A *, to match a version number.
diff --git a/nsprpub/config/Makefile.in b/nsprpub/config/Makefile.in
index 19e6b82b5b8b..2234c79fb4b3 100644
--- a/nsprpub/config/Makefile.in
+++ b/nsprpub/config/Makefile.in
@@ -105,10 +105,6 @@ XCFLAGS = $(OS_EXE_CFLAGS)
 XLDOPTS = -Zlinker /PM:VIO
 endif
 
-ifeq ($(MOZ_OS2_TOOLS),VACPP)
-OS_CFLAGS = $(OS_EXE_CFLAGS)
-endif
-
 include $(topsrcdir)/config/rules.mk
 
 PROGS	= $(OBJDIR)/now$(PROG_SUFFIX)
@@ -135,7 +131,7 @@ export:: $(TARGETS)
 $(OBJDIR)/%$(PROG_SUFFIX): $(OBJDIR)/%.$(OBJ_SUFFIX)
 	@$(MAKE_OBJDIR)
 ifeq ($(MOZ_OS2_TOOLS),VACPP)
-	$(LINK) $(EXEFLAGS) $<
+	$(LD) $(EXEFLAGS) $<
 else
 	$(CC) $(XCFLAGS) $< $(XLDOPTS) $(OUTOPTION)$@
 endif
diff --git a/nsprpub/config/autoconf.mk.in b/nsprpub/config/autoconf.mk.in
index bae8076e5278..9e33b8a0e69f 100644
--- a/nsprpub/config/autoconf.mk.in
+++ b/nsprpub/config/autoconf.mk.in
@@ -45,6 +45,8 @@ WINDRES		= @WINDRES@
 RC		= @RC@
 STRIP		= @STRIP@
 NSINSTALL	= @NSINSTALL@
+FILTER		= @FILTER@
+IMPLIB		= @IMPLIB@
 
 OS_CFLAGS	= @CFLAGS@ $(DSO_CFLAGS)
 OS_CXXFLAGS	= @CXXFLAGS@ $(DSO_CFLAGS)
@@ -52,6 +54,7 @@ OS_LIBS         = @OS_LIBS@
 OS_LDFLAGS	= @LDFLAGS@
 OS_DLLFLAGS	= @OS_DLLFLAGS@
 DLLFLAGS	= @DLLFLAGS@
+EXEFLAGS  = @EXEFLAGS@
 OPTIMIZER	= @OPTIMIZER@
 
 MKSHLIB		= @MKSHLIB@
diff --git a/nsprpub/config/config.mk b/nsprpub/config/config.mk
index 0a703678e189..781ec139a188 100644
--- a/nsprpub/config/config.mk
+++ b/nsprpub/config/config.mk
@@ -78,6 +78,9 @@ endef
 
 LINK_DLL	= $(LD) $(OS_DLLFLAGS) $(DLLFLAGS)
 
+ifneq (,$(filter WINNT OS2, $(OS_ARCH)))
+INSTALL		= $(NSINSTALL)
+else
 ifeq ($(NSDISTMODE),copy)
 # copy files, but preserve source mtime
 INSTALL		= $(NSINSTALL) -t
@@ -90,6 +93,7 @@ else
 INSTALL		= $(NSINSTALL) -R
 endif
 endif
+endif # WINNT || OS2
 
 ifdef BUILD_DEBUG_GC
 DEFINES		+= -DDEBUG_GC
diff --git a/nsprpub/config/rules.mk b/nsprpub/config/rules.mk
index 270092223962..ed9905ee6fb2 100644
--- a/nsprpub/config/rules.mk
+++ b/nsprpub/config/rules.mk
@@ -295,7 +295,7 @@ $(LIBRARY): $(OBJS)
 	@$(MAKE_OBJDIR)
 	rm -f $@
 ifeq ($(MOZ_OS2_TOOLS),VACPP)
-	$(AR) $(subst /,\\,$(OBJS)) $(AR_EXTRA_ARGS)
+	$(AR) $(subst /,\\,$(OBJS)) $(AR_FLAGS)
 else
 ifdef USE_AUTOCONF
 	$(AR) $(AR_FLAGS) $(OBJS) $(AR_EXTRA_ARGS)
diff --git a/nsprpub/configure b/nsprpub/configure
index 0124780904e6..e7db7f2d55a4 100755
--- a/nsprpub/configure
+++ b/nsprpub/configure
@@ -2434,7 +2434,7 @@ elif test "$OS_ARCH" = 'Windows_95'; then
 elif test "$OS_ARCH" = "CYGWIN_95-4.0"; then
     OS_ARCH='CYGWIN_NT-4.0'
     OS_TARGET=WIN95
-elif test "$OS_ARCH" = "OS2"; then
+elif test "$OS_ARCH" = "OS_2"; then
     OS_ARCH=OS2
     OS_TARGET=OS2
 fi
@@ -2528,6 +2528,8 @@ case "$host" in
 *-beos*)
     HOST_CFLAGS="$HOST_CFLAGS -DXP_BEOS -DBeOS -DBEOS -D_POSIX_SOURCE"
     ;;
+*os2*)
+    ;;
 *)
     HOST_CFLAGS="$HOST_CFLAGS -DXP_UNIX"
     ;;
@@ -4012,6 +4014,105 @@ EOF
     CPU_ARCH=x86
     ;;
 
+*-os2*)
+    cat >> confdefs.h <<\EOF
+#define XP_OS2 1
+EOF
+
+    cat >> confdefs.h <<\EOF
+#define BSD_SELECT 1
+EOF
+
+    cat >> confdefs.h <<\EOF
+#define XP_PC 1
+EOF
+
+    cat >> confdefs.h <<\EOF
+#define _PR_GLOBAL_THREADS_ONLY 1
+EOF
+
+    OBJ_SUFFIX=obj
+    LIB_SUFFIX=lib
+    DLL_SUFFIX=dll
+    DLLTOOL=''
+    RC=rc.exe
+    PR_MD_ARCH_DIR=os2
+    PROG_SUFFIX=.exe
+    NSINSTALL=nsinstall
+
+    case "$target" in
+    *-os2_emx)
+        cat >> confdefs.h <<\EOF
+#define XP_OS2_EMX 1
+EOF
+
+        cat >> confdefs.h <<\EOF
+#define OS2 1
+EOF
+
+        AR=emxomfar
+        AR_FLAGS='-p256 r $@'
+        CFLAGS="-Zmtd -Zomf"
+        HOST_CFLAGS="$CFLAGS"
+        CXXFLAGS="-Zmtd -Zomf"
+        OS_LIBS="-lsocket -lemxio"
+        LD='$(CC)'
+        IMPLIB='emximp -o'
+        FILTER='emxexp'
+        _OPTIMIZE_FLAGS=-O3
+        _DEBUG_FLAGS=-g
+        if test -n "$MOZ_DEBUG"; then
+          DLLFLAGS='-g'
+          EXEFLAGS='-g $(OMF_FLAG) -Zmtd -L$(DIST)/lib -o $@'
+        else
+          DLLFLAGS=
+          EXEFLAGS='-Zmtd -o $@'
+        fi
+        ;;
+    *-os2_vacpp)
+        cat >> confdefs.h <<\EOF
+#define XP_OS2_VACPP 1
+EOF
+
+        cat >> confdefs.h <<\EOF
+#define OS2 4
+EOF
+
+        cat >> confdefs.h <<\EOF
+#define TCPV40HDRS 1
+EOF
+
+        cat >> confdefs.h <<\EOF
+#define _X86_ 1
+EOF
+
+        AR=-ilib
+        AR_FLAGS='/NOL /NOI /O:$(subst /,\\,$@)'
+        CFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Mp /Tl-'
+        HOST_CFLAGS="$CFLAGS"
+        OS_CFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Ge- /Tl-'
+        OS_EXE_CFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Ge+ /Tl-'
+        CXXFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Mp /Tl-'
+        OS_LIBS='so32dll.lib tcp32dll.lib'
+        LD='-ilink'
+        LDFLAGS='/FREE /DE /NOE /LINENUMBERS /nologo'
+        MKSHLIB='$(LD) $(DSO_LDOPTS)'
+        IMPLIB='implib -nologo -noignorecase'
+        FILTER='cppfilt -q -B -P'
+        _OPTIMIZE_FLAGS=/O+
+        _DEBUG_FLAGS=/Ti+ 
+        if test -n "$MOZ_DEBUG"; then
+          DLLFLAGS='/O:$@ /DLL /INC:_dllentry /MAP:$(@:.dll=.map) /nologo /DEBUG /NOE'
+          EXEFLAGS='/OUT:$@ /PMTYPE:VIO /MAP:$(@:.exe=.map) /nologo /DEBUG /NOE'
+        else
+          DLLFLAGS='/O:$@ /DLL /INC:_dllentry /MAP:$(@:.dll=.map) /nologo'
+          EXEFLAGS='/OUT:$@ /PMTYPE:VIO /MAP:$(@:.exe=.map) /nologo'
+        fi
+        ;;
+    esac
+
+    ;;
+
 *)
     cat >> confdefs.h <<\EOF
 #define XP_UNIX 1
@@ -4028,12 +4129,12 @@ fi
 if test -z "$SKIP_LIBRARY_CHECKS"; then
 
 echo $ac_n "checking for dlopen""... $ac_c" 1>&6
-echo "configure:4032: checking for dlopen" >&5
+echo "configure:4133: checking for dlopen" >&5
 if eval "test \"`echo '$''{'ac_cv_func_dlopen'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 4037 "configure"
+#line 4138 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char dlopen(); below.  */
@@ -4056,7 +4157,7 @@ dlopen();
 
 ; return 0; }
 EOF
-if { (eval echo configure:4060: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:4161: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_func_dlopen=yes"
 else
@@ -4075,7 +4176,7 @@ else
   echo "$ac_t""no" 1>&6
 
     echo $ac_n "checking for dlopen in -ldl""... $ac_c" 1>&6
-echo "configure:4079: checking for dlopen in -ldl" >&5
+echo "configure:4180: checking for dlopen in -ldl" >&5
 ac_lib_var=`echo dl'_'dlopen | sed 'y%./+-%__p_%'`
 if eval "test \"`echo '$''{'ac_cv_lib_$ac_lib_var'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
@@ -4083,7 +4184,7 @@ else
   ac_save_LIBS="$LIBS"
 LIBS="-ldl  $LIBS"
 cat > conftest.$ac_ext <<EOF
-#line 4087 "configure"
+#line 4188 "configure"
 #include "confdefs.h"
 /* Override any gcc2 internal prototype to avoid an error.  */
 /* We use char because int might match the return type of a gcc2
@@ -4094,7 +4195,7 @@ int main() {
 dlopen()
 ; return 0; }
 EOF
-if { (eval echo configure:4098: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:4199: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_lib_$ac_lib_var=yes"
 else
@@ -4121,7 +4222,7 @@ fi
 
 
 echo $ac_n "checking how to run the C preprocessor""... $ac_c" 1>&6
-echo "configure:4125: checking how to run the C preprocessor" >&5
+echo "configure:4226: checking how to run the C preprocessor" >&5
 # On Suns, sometimes $CPP names a directory.
 if test -n "$CPP" && test -d "$CPP"; then
   CPP=
@@ -4136,13 +4237,13 @@ else
   # On the NeXT, cc -E runs the code through the compiler's parser,
   # not just through cpp.
   cat > conftest.$ac_ext <<EOF
-#line 4140 "configure"
+#line 4241 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:4146: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:4247: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -4153,13 +4254,13 @@ else
   rm -rf conftest*
   CPP="${CC-cc} -E -traditional-cpp"
   cat > conftest.$ac_ext <<EOF
-#line 4157 "configure"
+#line 4258 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:4163: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:4264: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -4170,13 +4271,13 @@ else
   rm -rf conftest*
   CPP="${CC-cc} -nologo -E"
   cat > conftest.$ac_ext <<EOF
-#line 4174 "configure"
+#line 4275 "configure"
 #include "confdefs.h"
 #include <assert.h>
 Syntax Error
 EOF
 ac_try="$ac_cpp conftest.$ac_ext >/dev/null 2>conftest.out"
-{ (eval echo configure:4180: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
+{ (eval echo configure:4281: \"$ac_try\") 1>&5; (eval $ac_try) 2>&5; }
 ac_err=`grep -v '^ *+' conftest.out | grep -v "^conftest.${ac_ext}\$"`
 if test -z "$ac_err"; then
   :
@@ -4202,13 +4303,13 @@ echo "$ac_t""$CPP" 1>&6
 
 if test $ac_cv_prog_gcc = yes; then
     echo $ac_n "checking whether ${CC-cc} needs -traditional""... $ac_c" 1>&6
-echo "configure:4206: checking whether ${CC-cc} needs -traditional" >&5
+echo "configure:4307: checking whether ${CC-cc} needs -traditional" >&5
 if eval "test \"`echo '$''{'ac_cv_prog_gcc_traditional'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
     ac_pattern="Autoconf.*'x'"
   cat > conftest.$ac_ext <<EOF
-#line 4212 "configure"
+#line 4313 "configure"
 #include "confdefs.h"
 #include <sgtty.h>
 Autoconf TIOCGETP
@@ -4226,7 +4327,7 @@ rm -f conftest*
 
   if test $ac_cv_prog_gcc_traditional = no; then
     cat > conftest.$ac_ext <<EOF
-#line 4230 "configure"
+#line 4331 "configure"
 #include "confdefs.h"
 #include <termio.h>
 Autoconf TCGETA
@@ -4250,12 +4351,12 @@ fi
 for ac_func in lchown strerror
 do
 echo $ac_n "checking for $ac_func""... $ac_c" 1>&6
-echo "configure:4254: checking for $ac_func" >&5
+echo "configure:4355: checking for $ac_func" >&5
 if eval "test \"`echo '$''{'ac_cv_func_$ac_func'+set}'`\" = set"; then
   echo $ac_n "(cached) $ac_c" 1>&6
 else
   cat > conftest.$ac_ext <<EOF
-#line 4259 "configure"
+#line 4360 "configure"
 #include "confdefs.h"
 /* System header to define __stub macros and hopefully few prototypes,
     which can conflict with char $ac_func(); below.  */
@@ -4278,7 +4379,7 @@ $ac_func();
 
 ; return 0; }
 EOF
-if { (eval echo configure:4282: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
+if { (eval echo configure:4383: \"$ac_link\") 1>&5; (eval $ac_link) 2>&5; } && test -s conftest${ac_exeext}; then
   rm -rf conftest*
   eval "ac_cv_func_$ac_func=yes"
 else
@@ -4309,7 +4410,7 @@ done
 
 
 echo $ac_n "checking for pthread_create in -lpthreads""... $ac_c" 1>&6
-echo "configure:4313: checking for pthread_create in -lpthreads" >&5
+echo "configure:4414: checking for pthread_create in -lpthreads" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { int a = 1;  } 
@@ -4331,7 +4432,7 @@ echo "
         echo "$ac_t""no" 1>&6
         
 echo $ac_n "checking for pthread_create in -lpthread""... $ac_c" 1>&6
-echo "configure:4335: checking for pthread_create in -lpthread" >&5
+echo "configure:4436: checking for pthread_create in -lpthread" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { int a = 1;  } 
@@ -4353,7 +4454,7 @@ echo "
         echo "$ac_t""no" 1>&6
         
 echo $ac_n "checking for pthread_create in -lc_r""... $ac_c" 1>&6
-echo "configure:4357: checking for pthread_create in -lc_r" >&5
+echo "configure:4458: checking for pthread_create in -lc_r" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { int a = 1;  } 
@@ -4375,7 +4476,7 @@ echo "
         echo "$ac_t""no" 1>&6
         
 echo $ac_n "checking for pthread_create in -lc""... $ac_c" 1>&6
-echo "configure:4379: checking for pthread_create in -lc" >&5
+echo "configure:4480: checking for pthread_create in -lc" >&5
 echo "
     #include <pthread.h> 
     void *foo(void *v) { int a = 1;  } 
@@ -4525,7 +4626,7 @@ if test -n "$USE_PTHREADS"; then
       rm -f conftest*
    ac_cv_have_dash_pthread=no
    echo $ac_n "checking whether ${CC-cc} accepts -pthread""... $ac_c" 1>&6
-echo "configure:4529: checking whether ${CC-cc} accepts -pthread" >&5
+echo "configure:4630: checking whether ${CC-cc} accepts -pthread" >&5
    echo 'int main() { return 0; }' | cat > conftest.c
    ${CC-cc} -pthread -o conftest conftest.c > conftest.out 2>&1
    if test $? -eq 0; then
@@ -4541,7 +4642,7 @@ echo "configure:4529: checking whether ${CC-cc} accepts -pthread" >&5
 			    ac_cv_have_dash_pthreads=no
     if test "$ac_cv_have_dash_pthread" = "no"; then
 	    echo $ac_n "checking whether ${CC-cc} accepts -pthreads""... $ac_c" 1>&6
-echo "configure:4545: checking whether ${CC-cc} accepts -pthreads" >&5
+echo "configure:4646: checking whether ${CC-cc} accepts -pthreads" >&5
     	echo 'int main() { return 0; }' | cat > conftest.c
 	    ${CC-cc} -pthreads -o conftest conftest.c > conftest.out 2>&1
     	if test $? -eq 0; then
@@ -4786,6 +4887,9 @@ fi
 
 
 
+
+
+
 
 
 
@@ -5040,6 +5144,8 @@ s%@OS_TEST@%$OS_TEST%g
 s%@DEFINES@%$DEFINES%g
 s%@AR_FLAGS@%$AR_FLAGS%g
 s%@ASFLAGS@%$ASFLAGS%g
+s%@FILTER@%$FILTER%g
+s%@IMPLIB@%$IMPLIB%g
 s%@OS_LIBS@%$OS_LIBS%g
 s%@RESOLVE_LINK_SYMBOLS@%$RESOLVE_LINK_SYMBOLS%g
 s%@AIX_LINK_OPTS@%$AIX_LINK_OPTS%g
@@ -5054,6 +5160,7 @@ s%@OPTIMIZER@%$OPTIMIZER%g
 s%@RC@%$RC%g
 s%@CPU_ARCH_TAG@%$CPU_ARCH_TAG%g
 s%@DLLFLAGS@%$DLLFLAGS%g
+s%@EXEFLAGS@%$EXEFLAGS%g
 s%@OS_DLLFLAGS@%$OS_DLLFLAGS%g
 
 CEOF
diff --git a/nsprpub/configure.in b/nsprpub/configure.in
index 10e0ca593400..2839c5d61ef4 100644
--- a/nsprpub/configure.in
+++ b/nsprpub/configure.in
@@ -369,7 +369,7 @@ elif test "$OS_ARCH" = 'Windows_95'; then
 elif test "$OS_ARCH" = "CYGWIN_95-4.0"; then
     OS_ARCH='CYGWIN_NT-4.0'
     OS_TARGET=WIN95
-elif test "$OS_ARCH" = "OS2"; then
+elif test "$OS_ARCH" = "OS_2"; then
     OS_ARCH=OS2
     OS_TARGET=OS2
 fi
@@ -467,6 +467,8 @@ case "$host" in
 *-beos*)
     HOST_CFLAGS="$HOST_CFLAGS -DXP_BEOS -DBeOS -DBEOS -D_POSIX_SOURCE"
     ;;
+*os2*)
+    ;;
 *)
     HOST_CFLAGS="$HOST_CFLAGS -DXP_UNIX"
     ;;
@@ -1381,6 +1383,75 @@ mips-sony-newsos*)
     CPU_ARCH=x86
     ;;
 
+*-os2*)
+    AC_DEFINE(XP_OS2)
+    AC_DEFINE(BSD_SELECT)
+    AC_DEFINE(XP_PC)
+    AC_DEFINE(_PR_GLOBAL_THREADS_ONLY)
+    OBJ_SUFFIX=obj
+    LIB_SUFFIX=lib
+    DLL_SUFFIX=dll
+    DLLTOOL=''
+    RC=rc.exe
+    PR_MD_ARCH_DIR=os2
+    PROG_SUFFIX=.exe
+    NSINSTALL=nsinstall
+
+    case "$target" in
+    *-os2_emx)
+        AC_DEFINE(XP_OS2_EMX)
+        AC_DEFINE(OS2)
+        AR=emxomfar
+        AR_FLAGS='-p256 r $@'
+        CFLAGS="-Zmtd -Zomf"
+        HOST_CFLAGS="$CFLAGS"
+        CXXFLAGS="-Zmtd -Zomf"
+        OS_LIBS="-lsocket -lemxio"
+        LD='$(CC)'
+        IMPLIB='emximp -o'
+        FILTER='emxexp'
+        _OPTIMIZE_FLAGS=-O3
+        _DEBUG_FLAGS=-g
+        if test -n "$MOZ_DEBUG"; then
+          DLLFLAGS='-g'
+          EXEFLAGS='-g $(OMF_FLAG) -Zmtd -L$(DIST)/lib -o $@'
+        else
+          DLLFLAGS=
+          EXEFLAGS='-Zmtd -o $@'
+        fi
+        ;;
+    *-os2_vacpp)
+        AC_DEFINE(XP_OS2_VACPP)
+        AC_DEFINE(OS2,4)
+        AC_DEFINE(TCPV40HDRS)
+        AC_DEFINE(_X86_)
+        AR=-ilib
+        AR_FLAGS='/NOL /NOI /O:$(subst /,\\,$@)'
+        CFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Mp /Tl-'
+        HOST_CFLAGS="$CFLAGS"
+        OS_CFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Ge- /Tl-'
+        OS_EXE_CFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Ge+ /Tl-'
+        CXXFLAGS='/Q /qlibansi /Gd+ /Gm+ /Su4 /Mp /Tl-'
+        OS_LIBS='so32dll.lib tcp32dll.lib'
+        LD='-ilink'
+        LDFLAGS='/FREE /DE /NOE /LINENUMBERS /nologo'
+        MKSHLIB='$(LD) $(DSO_LDOPTS)'
+        IMPLIB='implib -nologo -noignorecase'
+        FILTER='cppfilt -q -B -P'
+        _OPTIMIZE_FLAGS=/O+
+        _DEBUG_FLAGS=/Ti+ 
+        if test -n "$MOZ_DEBUG"; then
+          DLLFLAGS='/O:$@ /DLL /INC:_dllentry /MAP:$(@:.dll=.map) /nologo /DEBUG /NOE'
+          EXEFLAGS='/OUT:$@ /PMTYPE:VIO /MAP:$(@:.exe=.map) /nologo /DEBUG /NOE'
+        else
+          DLLFLAGS='/O:$@ /DLL /INC:_dllentry /MAP:$(@:.dll=.map) /nologo'
+          EXEFLAGS='/OUT:$@ /PMTYPE:VIO /MAP:$(@:.exe=.map) /nologo'
+        fi
+        ;;
+    esac
+
+    ;;
+
 *)
     AC_DEFINE(XP_UNIX)
     ;;
@@ -1808,6 +1879,8 @@ AC_SUBST(WINDRES)
 AC_SUBST(RANLIB)
 AC_SUBST(PERL)
 AC_SUBST(STRIP)
+AC_SUBST(FILTER)
+AC_SUBST(IMPLIB)
 
 AC_SUBST(OS_LIBS)
 AC_SUBST(RESOLVE_LINK_SYMBOLS)
@@ -1824,6 +1897,7 @@ AC_SUBST(OPTIMIZER)
 AC_SUBST(RC)
 AC_SUBST(CPU_ARCH_TAG)
 AC_SUBST(DLLFLAGS)
+AC_SUBST(EXEFLAGS)
 AC_SUBST(OS_DLLFLAGS)
 
 dnl ========================================================
diff --git a/nsprpub/pr/src/md/os2/Makefile.in b/nsprpub/pr/src/md/os2/Makefile.in
index b9621a0581e1..73d8a08e94db 100644
--- a/nsprpub/pr/src/md/os2/Makefile.in
+++ b/nsprpub/pr/src/md/os2/Makefile.in
@@ -60,7 +60,7 @@ endif
 
 TARGETS	= $(OBJS)
 
-INCLUDES = -I$(includedir) -I$(MOD_DEPTH)/pr/include -I$(MOD_DEPTH)/pr/include/private
+INCLUDES = -I$(includedir) -I$(topsrcdir)/pr/include -I$(topsrcdir)/pr/include/private
 
 DEFINES	+= -D_NSPR_BUILD_