diff --git a/Makefile.in b/Makefile.in
index f04307d7e..00fd4d5f9 100755
--- a/Makefile.in
+++ b/Makefile.in
@@ -614,7 +614,7 @@ install_win32: startup.yss @WINDOWS@ yap-win@EXEC_SUFFIX@ install_unix
 	$(INSTALL_PROGRAM) -m 755 yap.dll $(DESTDIR)$(BINDIR)/yap.dll
 	@WINDOWS@ $(INSTALL_PROGRAM) -m 755 yap-win.exe $(DESTDIR)$(BINDIR)/yap-win.exe
 	@WINDOWS@ $(INSTALL_PROGRAM) -m 755 yap.exe $(DESTDIR)$(BINDIR)/yap.exe
-	@WINDOWS@ $(INSTALL_PROGRAM) -m 755 plterm.dll $(DESTDIR)$(BINDIR)/plterm.dll
+	@WINDOWS@ for i in *.dll; do $(INSTALL_PROGRAM) -m 755 $$i $(DESTDIR)$(BINDIR)/; done
 	$(INSTALL_DATA) $(srcdir)/misc/icons/yap.ico $(DESTDIR)$(SHAREDIR)/Yap/icons
 
 install_library: @YAPLIB@
diff --git a/configure b/configure
index b5bab8589..6199ab952 100755
--- a/configure
+++ b/configure
@@ -835,7 +835,6 @@ ac_subst_files=''
 ac_user_opts='
 enable_option_checking
 enable_tabling
-enable_abi
 enable_or_parallelism
 enable_depth_limit
 enable_wam_profile
@@ -1512,7 +1511,6 @@ Optional Features:
   --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
   --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
  --enable-tabling           support tabling
- --enable-abi           support tabling
  --enable-or-parallelism    support or-parallelism as: copy,sba,a-cow,threads
  --enable-depth-limit       support depth-bound computation
  --enable-wam-profile       support low level profiling of abstract machine
@@ -4209,15 +4207,6 @@ else
   tabling=yes
 fi
 
-# Check whether --enable-abi was given.
-if test "${enable_abi+set}" = set; then :
-  enableval=$enable_abi; yap_cv_abi="$enableval"
-         CC="$CC -m$abi"
-         CXX="$CXX -m$abi"
-else
-  yap_cv_abi=""
-fi
-
 # Check whether --enable-or-parallelism was given.
 if test "${enable_or_parallelism+set}" = set; then :
   enableval=$enable_or_parallelism; orparallelism="$enableval"
@@ -4557,9 +4546,7 @@ $as_echo "#define MinStackSpace (1024*SIZEOF_INT_P)" >>confdefs.h
 
 $as_echo "#define MinTrailSpace (256*SIZEOF_INT_P)" >>confdefs.h
 
-  $as_echo "#define MAX_WORKERS 1" >>confdefs.h
-
-if test "$orparallelism" = no
+if test "$orparallelism" = yes
 then
 
 cat >>confdefs.h <<_ACEOF
@@ -4574,6 +4561,9 @@ _ACEOF
   then
     threads="yes"
   fi
+else
+  $as_echo "#define MAX_WORKERS 1" >>confdefs.h
+
 fi
 
 
@@ -12175,7 +12165,7 @@ else
 JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 cat << \EOF > $JAVA_TEST
-/* #line 12178 "configure" */
+/* #line 12168 "configure" */
 public class Test {
 }
 EOF
@@ -12351,7 +12341,7 @@ EOF
 if uudecode$EXEEXT Test.uue; then
         ac_cv_prog_uudecode_base64=yes
 else
-        echo "configure: 12354: uudecode had trouble decoding base 64 file 'Test.uue'" >&5
+        echo "configure: 12344: uudecode had trouble decoding base 64 file 'Test.uue'" >&5
         echo "configure: failed file was:" >&5
         cat Test.uue >&5
         ac_cv_prog_uudecode_base64=no
@@ -12482,7 +12472,7 @@ else
 JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 cat << \EOF > $JAVA_TEST
-/* #line 12485 "configure" */
+/* #line 12475 "configure" */
 public class Test {
 }
 EOF
@@ -12517,7 +12507,7 @@ JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 TEST=Test
 cat << \EOF > $JAVA_TEST
-/* [#]line 12520 "configure" */
+/* [#]line 12510 "configure" */
 public class Test {
 public static void main (String args[]) {
         System.exit (0);
diff --git a/configure.in b/configure.in
index b45e624b7..1975eb179 100755
--- a/configure.in
+++ b/configure.in
@@ -101,11 +101,6 @@ AC_DEFINE(ALIGN_LONGS, 1, [longs should be in addresses that are multiple of fou
 AC_ARG_ENABLE(tabling,
 	[ --enable-tabling           support tabling ],
 	tabling="$enableval", tabling=yes)
-AC_ARG_ENABLE(abi,
-	[ --enable-abi           support tabling ],
-	[yap_cv_abi="$enableval"
-         CC="$CC -m$abi"
-         CXX="$CXX -m$abi"], yap_cv_abi="")
 AC_ARG_ENABLE(or-parallelism,
 	[ --enable-or-parallelism    support or-parallelism as: copy,sba,a-cow,threads ],
 	orparallelism="$enableval", orparallelism=no)
@@ -313,8 +308,7 @@ AC_ARG_WITH(max-threads,
   AC_DEFINE(MinHeapSpace, (2048*SIZEOF_INT_P), [at least 2M Cells for Heap])
   AC_DEFINE(MinStackSpace,(1024*SIZEOF_INT_P), [at least 1M Cells for Stack]) 
   AC_DEFINE(MinTrailSpace,(256*SIZEOF_INT_P), [at least 1/2M Cells for Trail])
-  AC_DEFINE(MAX_WORKERS,1)
-if test "$orparallelism" = no
+if test "$orparallelism" = yes
 then
   AC_DEFINE_UNQUOTED(MAX_WORKERS,$yap_cv_max_workers,[maximum amount of or-parallelism])
   if test "$orparallelism" = copy -o "$orparallelism" = yes
@@ -325,6 +319,8 @@ then
   then
     threads="yes"
   fi
+else
+  AC_DEFINE(MAX_WORKERS,1)
 fi
 
 AC_DEFINE_UNQUOTED(DefHeapSpace,$yap_cv_heap_space, [Default Heap Space.])
diff --git a/misc/mkwin b/misc/mkwin
index 45f7020ca..9c3e7c49b 100755
--- a/misc/mkwin
+++ b/misc/mkwin
@@ -1,4 +1,15 @@
-
+#!/bin/sh
+#
+# script for compiling and installing YAP under msys. Uses a mingw64
+# compiler and nsis to do the installing
+#
+# please check:
+#
+# http://sourceforge.net/projects/mingwbuilds/
+# http://nsis.sourceforge.net/Main_Page
+#
+#
+VERSION=6.3.4
 THREADS=yes
 if test $# = 0; then
   ABI=64
@@ -9,8 +20,21 @@ else
   THREADS=$2
 fi
 
+# debugging setup
+do_compile=true
+do_install=true
+
 # HOME WIN64 configuration
-if test -e "/c/cygwin/Yap/mingw64/bin/gcc" -a $ABI = 64; then
+
+DOCS_DIR=/z/Yap/bins/osx
+if test "$THREADS" = yes; then
+  FULL_VERSION="$VERSION"-threads
+else
+  FULL_VERSION="$VERSION"
+fi
+
+if test $ABI = 64; then
+GCC_PATH=/c/cygwin/Yap/mingw64
 CUDD=yes
 GECODE=no #does not link with mingw64, VC++ trouble
 GMP=yes
@@ -18,13 +42,7 @@ JAVA=yes
 PYTHON=no
 REAL=yes
 HOST="--host=x86_64-w64-mingw32"
-if test $THREADS = yes; then
-  TAR=yap-x86_64-threads-6.3.4.tar.gz
-else
-  TAR=yap-x86_64-6.3.4.tar.gz
-fi
 
-  GCC_PATH="/c/cygwin/Yap/mingw64"
   # it seems python2.7 does not support mingw64
   PYTHON_PATH="/c/Python33-64"
   export PATH="$GCC_PATH"/bin:"$PATH"
@@ -42,7 +60,8 @@ fi
 fi
 
 # HOME WIN32 configuration
-if test -e "/c/cygwin/Yap/mingw64/bin/gcc" -a $ABI = 32; then
+if test $ABI = 32; then
+GCC_PATH="/c/Program Files (x86)/mingw-builds/x32-4.8.1-posix-dwarf-rev5/mingw32"
 CUDD=yes
 GECODE=no # install only allows one of 32 or 64 bits
 GMP=yes
@@ -50,7 +69,6 @@ JAVA=yes
 PYTHON=no
 REAL=yes
 
-  GCC_PATH="/c/cygwin/Yap/mingw64"
   PYTHON_PATH="/c/Python27"
   export PATH="$GCC_PATH"/bin:$PATH:"$PYTHON_PATH"
 #  GECODE_PATH="/c/Program Files/Gecode"
@@ -59,10 +77,11 @@ REAL=yes
   JAVA_PATH="/c/Program Files (x86)/Java/jdk1.7.0_51"
   R_PATH="/c/Program Files/R/R-3.0.2"
   R_ABI=i386
-  HOST="--enable-abi=32"
+  HOST=""
+
   if test $THREADS = yes
   then
-    cp "$GCC_PATH/x86_64-w64-mingw32/lib32/libwinpthread-1.dll" .
+      cp "$GCC_PATH/i686-w64-mingw32/lib/libwinpthread-1.dll" .
     cp libwinpthread-1.dll pthreadGC2.dll
   fi
 fi
@@ -92,6 +111,7 @@ then
   export PATH="$PATH":"$R_PATH"/bin/"$R_ABI"
 fi
 
+if test "$do_compile" = true; then
 ../yap-6.3/configure $HOST \
 	--with-R="$REAL" \
 	--with-java="$JAVA" \
@@ -102,10 +122,15 @@ fi
 	--enable-threads="$THREADS"  --enable-pthread-locking \
 	 --enable-debug-yap --enable-low-level-tracer
 make install
-cp /z/Yap/bins/osx/*html /c/Yap64/share/doc/Yap
-cp /z/Yap/bins/osx/*pdf /c/Yap64/share/doc/Yap
-if test $ABI = 64; then
-  "/c/Program Files (x86)/NSIS/makensis" ../yap-6.3/misc/Yap64.nsi
-else
-  "/c/Program Files (x86)/NSIS/makensis" ../yap-6.3/misc/Yap.nsi
+fi
+if test "$do_install" = true; then
+if test $ABI = 64; then
+  cp $DOCS_DIR/*html /c/Yap64/share/doc/Yap
+  cp $DOCS_DIR/*pdf /c/Yap64/share/doc/Yap
+  "/c/Program Files (x86)/NSIS/makensis" -DREGKEY=SOFTWARE\\YAP\\Prolog64 -DROOTDIR=Yap64 -DABI="$ABI" -DVERSION="$FULL_VERSION" -DOPTIONS="..\\yap-6.3\\misc\\options.ini" -DOUT_DIR=".." -D"WIN64=1" -NOCD ../yap-6.3/misc/Yap.nsi
+else
+  cp $DOCS_DIR/*html /c/Yap/share/doc/Yap
+  cp $DOCS_DIR/*pdf /c/Yap/share/doc/Yap
+  "/c/Program Files (x86)/NSIS/makensis" -DREGKEY=SOFTWARE\\YAP\\Prolog -DROOTDIR=Yap -DABI="$ABI" -DVERSION="$FULL_VERSION" -DOPTIONS="..\\yap-6.3\\misc\\options.ini" -DOUT_DIR=".." -NOCD ../yap-6.3/misc/Yap.nsi
+fi
 fi
diff --git a/misc/yap.nsi b/misc/yap.nsi
index 0f5e1aaba..9bbcecc96 100755
--- a/misc/yap.nsi
+++ b/misc/yap.nsi
@@ -1,4 +1,4 @@
-# YAP install-script (from SWI-Prolog)
+; YAP install-script (based on a similar scrip from SWI-Prolog)
 
 !define TEMP1 $R0 ; Temp variable
 !define EXT    $3 ; Filename extension for Prolog sources
@@ -7,31 +7,31 @@
 !define SHCTX  $6 ; Shell context (current/all)
 !define ARCH   $7 ; Architecture (x86, ia64 or amd64)
 
-!ifdef WIN64
-!define REGKEY SOFTWARE\YAP\Prolog64
-!else
-!define REGKEY SOFTWARE\YAP\Prolog
-!endif
-
-
 RequestExecutionLevel admin
-SetCompressor bzip2
 MiscButtonText "<back" "next>" "abort" "finished"
 
-# Preload files that are needed by the installer itself
-ReserveFile "${NSISDIR}\Plugins\UserInfo.dll"
-ReserveFile "${NSISDIR}\Plugins\InstallOptions.dll"
-ReserveFile "options.ini"
+SetCompressor /FINAL bzip2
+  
+; Preload files that are needed by the installer itself
+ReserveFile "${NSISDIR}\Plugins\x86-unicode\UserInfo.dll"
+ReserveFile "${NSISDIR}\Plugins\\x86-unicode\InstallOptions.dll"
+ReserveFile "${OPTIONS}"
 
-InstallDir $PROGRAMFILES\Yap
+!ifdef WIN64
+InstallDir "$PROGRAMFILES64\${ROOTDIR}"
+!else
+InstallDir "$PROGRAMFILES\${ROOTDIR}"
+!endif
 InstallDirRegKey HKLM ${REGKEY} "home"
+
 ComponentText "This will install YAP on your computer."
 DirText "This program will install YAP on your computer.\
          Choose a directory"
 
-LicenseData c:\Yap\share\doc\Yap\Artistic
-LicenseText "YAP is governed by the Artistic License,\
-	but includes code under the GPL and LGPL."
+Icon        c:\${ROOTDIR}\share\Yap\icons\yap.ico
+LicenseData c:\${ROOTDIR}\share\doc\Yap\Artistic
+LicenseText "YAP is governed by the Artistic License and LGPL;\
+	it includes code under the GPL and LGPL."
 
 InstType "Typical (all except debug symbols)"	# 1
 InstType "Minimal (no graphics)"		# 2
@@ -43,44 +43,55 @@ Page custom SetCustom "" ": Installation options"
 Page instfiles
 
 Section "Base system (required)"
+
   SectionIn RO			# do not allow to delete this
+  
+!ifdef WIN64
+  SetRegView 64
+!endif
 
   Delete $INSTDIR\bin\*.pdb
 
   SetOutPath $INSTDIR\bin
-  File c:\Yap\bin\yap.exe
-  File c:\Yap\bin\yap.dll
-  File c:\Yap\bin\yap-win.exe
-  File c:\Yap\bin\plterm.dll
+  File c:\${ROOTDIR}\bin\yap.exe
+  File c:\${ROOTDIR}\bin\yap.dll
+  File c:\${ROOTDIR}\bin\yap-win.exe
+  File c:\${ROOTDIR}\bin\*.dll
 
-  SetOutPath $INSTDIR\bin
+; first, copy library DLLs
+  SetOutPath $INSTDIR\lib\Yap
 ; SYSTEM STUFF
-  File c:\Yap\lib\Yap\*.dll
+  File c:\${ROOTDIR}\lib\Yap\*.dll
 
-  SetOutPath $INSTDIR\lib
-
-  SetOutPath $INSTDIR\lib
+  SetOutPath $INSTDIR\lib\Yap
 ; SYSTEM STUFF
-  File c:\Yap\lib\Yap\startup.yss
-
-  SetOutPath $INSTDIR\share
+  File c:\${ROOTDIR}\lib\Yap\startup.yss
+  
+  SetOutPath $INSTDIR\share\Yap
 ; SYSTEM STUFF
-  File /r c:\Yap\share\Yap\*
+  File /r c:\${ROOTDIR}\share\Yap\*
 
-  SetOutPath $INSTDIR\doc\Yap
-  File c:\Yap\share\doc\Yap\yap.html
-  File c:\Yap\share\doc\Yap\yap.pdf
-  File c:\Yap\share\doc\Yap\Artistic
-  File c:\Yap\share\doc\Yap\README.TXT
-  File c:\Yap\share\doc\Yap\COPYING.TXT
+  SetOutPath $INSTDIR\share\doc\Yap
+  File c:\${ROOTDIR}\share\doc\Yap\yap.html
+  File c:\${ROOTDIR}\share\doc\Yap\yap.pdf
+;  File c:\${ROOTDIR}\share\doc\Yap\yap.info
+  File c:\${ROOTDIR}\share\doc\Yap\Artistic
+  File c:\${ROOTDIR}\share\doc\Yap\README
+  File c:\${ROOTDIR}\share\doc\Yap\COPYING
 
   WriteRegStr HKLM ${REGKEY} "home" "$INSTDIR"
-  WriteRegStr HKLM ${REGKEY} "startup" "$INSTDIR\lib\startup.yss"
-  WriteRegStr HKLM ${REGKEY} "library" "$INSTDIR\share"
+  WriteRegStr HKLM ${REGKEY} "bin" "$INSTDIR\bin\yap.exe"
+  WriteRegStr HKLM ${REGKEY} "dlls" "$INSTDIR\lib\Yap"
+  WriteRegStr HKLM ${REGKEY} "startup" "$INSTDIR\lib\Yap\startup.yss"
+  WriteRegStr HKLM ${REGKEY} "library" "$INSTDIR\share\Yap"
+  WriteRegStr HKLM ${REGKEY} "commons" "$INSTDIR\share\PrologCommons"
 
   ; Write uninstaller
+!ifdef WIN64
+  WriteRegStr HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP64" "DisplayName" "YAP64 (remove only)"
+!else
   WriteRegStr HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP" "DisplayName" "YAP (remove only)"
-  WriteRegStr HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP" "UninstallString" '"$INSTDIR\uninstall.exe"'
+!endif
   WriteUninstaller "uninstall.exe"
 SectionEnd
 
@@ -88,24 +99,33 @@ SectionEnd
 Section "Start Menu shortcuts"
   SectionIn 1 2 3
   SetOutPath ${CWD}
+!ifdef WIN64
+  StrCpy ${GRP} "YAP64"
+!else
+  StrCpy ${GRP} "YAP"
+!endif
   CreateDirectory "$SMPROGRAMS\${GRP}"
   CreateShortCut "$SMPROGRAMS\${GRP}\YAP-WIN.lnk" \
 		 "$INSTDIR\bin\yap-win.exe" \
 		 "" \
 		 "$INSTDIR\bin\yap-win.exe" \
 		 0
-  SetOutPath $INSTDIR
+  CreateShortCut "$SMPROGRAMS\${GRP}\YAP.lnk" \
+		 "$INSTDIR\bin\yap.exe" \
+		 "" \
+		 "$INSTDIR\bin\yap.exe" \
+		 0
   CreateShortCut "$SMPROGRAMS\${GRP}\Readme.lnk" \
-  		  "$INSTDIR\doc\Yap\README.TXT" "" \
-		  "$INSTDIR\doc\Yap\README.TXT" 0 \
+  		  "$INSTDIR\share\doc\Yap\README" "" \
+		  "$INSTDIR\share\doc\Yap\README" 0 \
 		  "SW_SHOWNORMAL" "" "View readme"
   CreateShortCut "$SMPROGRAMS\${GRP}\Manual Html.lnk" \
-  		  "$INSTDIR\doc\Yap\yap.html" "" \
-		  "$INSTDIR\doc\Yap\yap.html" 0 \
+  		  "$INSTDIR\share\doc\Yap\yap.html" "" \
+		  "$INSTDIR\share\doc\Yap\yap.html" 0 \
 		  "SW_SHOWNORMAL" "" "View readme"
   CreateShortCut "$SMPROGRAMS\${GRP}\Manual PDF.lnk" \
-  		  "$INSTDIR\doc\Yap\yap.pdf" "" \
-		  "$INSTDIR\doc\Yap\yap.pdf" 0 \
+  		  "$INSTDIR\share\doc\Yap\yap.pdf" "" \
+		  "$INSTDIR\share\doc\Yap\yap.pdf" 0 \
 		  "SW_SHOWNORMAL" "" "View readme"
   CreateShortCut "$SMPROGRAMS\${GRP}\Uninstall.lnk" \
 		 "$INSTDIR\uninstall.exe" \
@@ -113,6 +133,7 @@ Section "Start Menu shortcuts"
 		 "$INSTDIR\uninstall.exe" \
 		 0
 
+  WriteRegStr HKLM ${REGKEY} fileExtension   ${EXT}
   WriteRegStr HKLM ${REGKEY} group   ${GRP}
   WriteRegStr HKLM ${REGKEY} cwd     ${CWD}
   WriteRegStr HKLM ${REGKEY} context ${SHCTX}
@@ -122,23 +143,46 @@ SectionEnd
 # The uninstaller
 ################################################################
 
-UninstallText "This will uninstall YAP. Hit Uninstall to continue."
+!ifdef WIN64
+  UninstallText "This will uninstall YAP64. Hit Uninstall to continue."
+!else
+  UninstallText "This will uninstall YAP. Hit Uninstall to continue."
+!endif
 
 Section "Uninstall"
-  ReadRegStr ${EXT}   HKLM Software\YAP\Prolog fileExtension
-  ReadRegStr ${GRP}   HKLM Software\YAP\Prolog group
-  ReadRegStr ${SHCTX} HKLM Software\YAP\Prolog context
+!ifdef WIN64
+  SetRegView 64
+!endif
+
+  ReadRegStr ${EXT}   HKLM ${REGKEY} fileExtension
+  StrCmp ${EXT} "" 0 UExt
+    StrCpy ${EXT} "pl"
+  UExt:
+
+  ReadRegStr ${GRP}   HKLM ${REGKEY} group
+  StrCmp ${GRP} "" 0 UHasGroup
+!ifdef WIN64
+    StrCpy ${GRP} "YAP64"
+!else
+    StrCpy ${GRP} "YAP"
+!endif
+  UHasGroup:
+
+  ReadRegStr ${SHCTX} HKLM ${REGKEY} context
+  StrCmp ${SHCTX} "" 0 UHasContext
+    StrCpy ${SHCTX} "all"
+  UHasContext:
 
   StrCmp ${SHCTX} "all" 0 +2
     SetShellVarContext all
 
-  MessageBox MB_YESNO "Delete the following components?$\r$\n \
+  MessageBox MB_YESNO "Delete the following components?\r$\n \
                        Install dir: $INSTDIR$\r$\n \
 		       Extension: ${EXT}$\r$\n \
 		       Program Group ${GRP}" \
 		      IDNO Done
 
-  StrCmp ".${EXT}" "" NoExt
+  StrCmp "${EXT}" "" NoExt
     ReadRegStr $1 HKCR .${EXT} ""
     StrCmp $1 "PrologFile" 0 NoOwn ; only do this if we own it
       ReadRegStr $1 HKCR .${EXT} "backup_val"
@@ -164,7 +208,12 @@ Section "Uninstall"
     MessageBox MB_OK "Folder $INSTDIR doesn't seem to contain Prolog"
 
   Done:
+!ifdef WIN64
+    DeleteRegKey HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP64"
+!else
     DeleteRegKey HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP"
+!endif
+
     DeleteRegKey HKLM ${REGKEY}
 SectionEnd
 
@@ -178,7 +227,7 @@ Function .onInit
   ;$PLUGINSDIR will automatically be removed when the installer closes
   
   InitPluginsDir
-  File /oname=$PLUGINSDIR\options.ini "options.ini"
+  File /oname=$PLUGINSDIR\options.ini "${OPTIONS}"
 
 FunctionEnd
 
@@ -193,6 +242,9 @@ FunctionEnd
 ################################################################
 
 Function SetCustom
+!ifdef WIN64
+  SetRegView 64
+!endif
 # Basic system info
   Call UserInfo
 
@@ -203,10 +255,16 @@ Function SetCustom
   HasExt:
   WriteINIStr $PLUGINSDIR\options.ini "Field 4" "State" ${EXT}  
 
+  StrCpy ${CWD} $INSTDIR
+
 # Startmenu program group
   ReadRegStr ${GRP} HKLM ${REGKEY} group
   StrCmp ${GRP} "" 0 HasGroup
+!ifdef WIN64
+    StrCpy ${GRP} "YAP64"
+!else
     StrCpy ${GRP} "YAP"
+!endif
   HasGroup:
   WriteINIStr $PLUGINSDIR\options.ini "Field 6" "State" ${GRP}  
 
@@ -219,6 +277,8 @@ Function SetCustom
 # Get the results
   ReadINIStr ${EXT} $PLUGINSDIR\options.ini "Field 4" "State"
   ReadINIStr ${GRP} $PLUGINSDIR\options.ini "Field 6" "State"
+  ReadINIStr ${GRP} $PLUGINSDIR\options.ini "Field 5" "State"
+
 FunctionEnd
 
 Function UserInfo
@@ -258,7 +318,7 @@ FunctionEnd
 
 Function .onInstSuccess
   MessageBox MB_YESNO "Installation complete. View readme?" IDNO NoReadme
-  ExecShell "open" "$INSTDIR\doc\README.TXT"
+  ExecShell "open" "$INSTDIR\share\doc\Yap\README"
   NoReadme:
 FunctionEnd
 
@@ -268,4 +328,4 @@ Function .onInstFailed
 		    installer, please contact yap-users@sf.net"
 FunctionEnd
 
-outfile "yap-6.3.4-installer.exe"
+outfile "${OUT_DIR}\yap${ABI}-${VERSION}-installer.exe"
diff --git a/misc/yap64.nsi b/misc/yap64.nsi
deleted file mode 100755
index c8520a40a..000000000
--- a/misc/yap64.nsi
+++ /dev/null
@@ -1,277 +0,0 @@
-; YAP install-script (based on a similar scrip from SWI-Prolog)
-
-!define TEMP1 $R0 ; Temp variable
-!define EXT    $3 ; Filename extension for Prolog sources
-!define CWD    $4 ; Working directory for startmenu shortcut
-!define GRP    $5 ; Startmenu group
-!define SHCTX  $6 ; Shell context (current/all)
-!define ARCH   $7 ; Architecture (x86, ia64 or amd64)
-!define REGKEY SOFTWARE\YAP\Prolog64
-
-RequestExecutionLevel admin
-SetCompressor bzip2
-MiscButtonText "<back" "next>" "abort" "finished"
-
-; Preload files that are needed by the installer itself
-ReserveFile "${NSISDIR}\Plugins\UserInfo.dll"
-ReserveFile "${NSISDIR}\Plugins\InstallOptions.dll"
-ReserveFile "options.ini"
-
-
-InstallDir $PROGRAMFILES64\Yap64
-InstallDirRegKey HKLM ${REGKEY} "home"
-ComponentText "This will install YAP64 on your computer."
-DirText "This program will install YAP64 on your computer.\
-         Choose a directory"
-
-Icon        c:\Yap64\share\Yap\icons\yap.ico
-LicenseData c:\Yap64\share\doc\Yap\Artistic
-LicenseText "YAP64 is governed by the Artistic License and LGPL;\
-	it includes code under the GPL and LGPL."
-
-InstType "Typical (all except debug symbols)"	# 1
-InstType "Minimal (no graphics)"		# 2
-InstType "Full"					# 3
-
-Page license
-Page directory
-Page custom SetCustom "" ": Installation options"
-Page instfiles
-
-Section "Base system (required)"
-  SectionIn RO			# do not allow to delete this
-  ; make sure we use 64 bits registry
-  SetRegView 64
-
-  Delete $INSTDIR\bin\*.pdb
-
-  SetOutPath $INSTDIR\bin
-  File c:\Yap64\bin\yap.exe
-  File c:\Yap64\bin\yap.dll
-  File c:\Yap64\bin\yap-win.exe
-  File c:\Yap64\bin\*.dll
-
-; first, copy library DLLs
-  SetOutPath $INSTDIR\lib\Yap
-; SYSTEM STUFF
-  File c:\Yap64\lib\Yap\*.dll
-
-  SetOutPath $INSTDIR\lib\Yap
-; SYSTEM STUFF
-  File c:\Yap64\lib\Yap\startup.yss
-  
-  SetOutPath $INSTDIR\share\Yap
-; SYSTEM STUFF
-  File /r c:\Yap64\share\Yap\*
-
-  SetOutPath $INSTDIR\share\doc\Yap
-  File c:\Yap64\share\doc\Yap\yap.html
-  File c:\Yap64\share\doc\Yap\yap.pdf
-  File c:\Yap64\share\doc\Yap\yap.html
-;  File c:\Yap64\share\doc\Yap\yap.info
-  File c:\Yap64\share\doc\Yap\Artistic
-  File c:\Yap64\share\doc\Yap\README.TXT
-  File c:\Yap64\share\doc\Yap\COPYING.TXT
-
-  WriteRegStr HKLM ${REGKEY} "home" "$INSTDIR"
-  WriteRegStr HKLM ${REGKEY} "bin" "$INSTDIR\bin\yap.exe"
-  WriteRegStr HKLM ${REGKEY} "dlls" "$INSTDIR\lib\Yap"
-  WriteRegStr HKLM ${REGKEY} "startup" "$INSTDIR\lib\Yap\startup.yss"
-  WriteRegStr HKLM ${REGKEY} "library" "$INSTDIR\share\Yap"
-  WriteRegStr HKLM ${REGKEY} "commons" "$INSTDIR\share\PrologCommons"
-
-  ; Write uninstaller
-  WriteRegStr HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP64" "DisplayName" "YAP64 (remove only)"
-  WriteRegStr HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP64" "UninstallString" '"$INSTDIR\uninstall.exe"'
-  WriteUninstaller "uninstall.exe"
-SectionEnd
-
-
-Section "Start Menu shortcuts"
-  SectionIn 1 2 3
-  SetOutPath ${CWD}
-  CreateDirectory "$SMPROGRAMS\${GRP}"
-  CreateShortCut "$SMPROGRAMS\${GRP}\YAP-WIN.lnk" \
-		 "$INSTDIR\bin\yap-win.exe" \
-		 "" \
-		 "$INSTDIR\bin\yap-win.exe" \
-		 0
-  CreateShortCut "$SMPROGRAMS\${GRP}\YAP.lnk" \
-		 "$INSTDIR\bin\yap.exe" \
-		 "" \
-		 "$INSTDIR\bin\yap.exe" \
-		 0
-  CreateShortCut "$SMPROGRAMS\${GRP}\Readme.lnk" \
-  		  "$INSTDIR\share\doc\Yap\README.TXT" "" \
-		  "$INSTDIR\share\doc\Yap\README.TXT" 0 \
-		  "SW_SHOWNORMAL" "" "View readme"
-  CreateShortCut "$SMPROGRAMS\${GRP}\Manual Html.lnk" \
-  		  "$INSTDIR\share\doc\Yap\yap.html" "" \
-		  "$INSTDIR\share\doc\Yap\yap.html" 0 \
-		  "SW_SHOWNORMAL" "" "View readme"
-  CreateShortCut "$SMPROGRAMS\${GRP}\Manual PDF.lnk" \
-  		  "$INSTDIR\share\doc\Yap\yap.pdf" "" \
-		  "$INSTDIR\share\doc\Yap\yap.pdf" 0 \
-		  "SW_SHOWNORMAL" "" "View readme"
-  CreateShortCut "$SMPROGRAMS\${GRP}\Uninstall.lnk" \
-		 "$INSTDIR\uninstall.exe" \
-		 "" \
-		 "$INSTDIR\uninstall.exe" \
-		 0
-
-  WriteRegStr HKLM ${REGKEY} group   ${GRP}
-  WriteRegStr HKLM ${REGKEY} cwd     ${CWD}
-  WriteRegStr HKLM ${REGKEY} context ${SHCTX}
-SectionEnd
-
-################################################################
-# The uninstaller
-################################################################
-
-UninstallText "This will uninstall YAP.64 Hit Uninstall to continue."
-
-Section "Uninstall"
-  ReadRegStr ${EXT}   HKLM Software\YAP\Prolog64 fileExtension
-  ReadRegStr ${GRP}   HKLM Software\YAP\Prolog64 group
-  ReadRegStr ${SHCTX} HKLM Software\YAP\Prolog64 context
-
-  StrCmp ${SHCTX} "all" 0 +2
-    SetShellVarContext all
-
-  MessageBox MB_YESNO "Delete the following components?$\r$\n \
-                       Install dir: $INSTDIR$\r$\n \
-		       Extension: ${EXT}$\r$\n \
-		       Program Group ${GRP}" \
-		      IDNO Done
-
-  StrCmp ".${EXT}" "" NoExt
-    ReadRegStr $1 HKCR .${EXT} ""
-    StrCmp $1 "PrologFile" 0 NoOwn ; only do this if we own it
-      ReadRegStr $1 HKCR .${EXT} "backup_val"
-      StrCmp $1 "" 0 RestoreBackup ; if backup == "" then delete the whole key
-	DeleteRegKey HKCR .${EXT}
-      Goto NoOwn
-      RestoreBackup:
-	WriteRegStr HKCR .${EXT} "" $1
-	DeleteRegValue HKCR .${EXT} "backup_val"
-    NoOwn:
-  NoExt:
-
-  StrCmp "${GRP}" "" NoGrp
-    MessageBox MB_OK "Deleting $SMPROGRAMS\${GRP}"
-    RMDir /r "$SMPROGRAMS\${GRP}"
-  NoGrp:
-
-  IfFileExists "$INSTDIR\bin\yap.exe" 0 NoDir
-    RMDir /r "$INSTDIR"
-    goto Done
-
-  NoDir:
-    MessageBox MB_OK "Folder $INSTDIR doesn't seem to contain Prolog"
-
-  Done:
-    DeleteRegKey HKLM "Software\Microsoft\Windows\CurrentVersion\Uninstall\YAP64"
-    DeleteRegKey HKLM ${REGKEY}
-SectionEnd
-
-################################################################
-# FUNCTIONS
-################################################################
-
-Function .onInit
-
-  ;Extract InstallOptions files
-  ;$PLUGINSDIR will automatically be removed when the installer closes
-  
-  InitPluginsDir
-  File /oname=$PLUGINSDIR\options.ini "options.ini"
-
-FunctionEnd
-
-################################################################
-# Handle customisation;  Settings are maintained in
-#
-# 	HKLM ${REGKEY}
-#
-# Using the following mapping:
-#
-#	${EXT} fileExtension
-################################################################
-
-Function SetCustom
-# Basic system info
-  Call UserInfo
-
-# Filename extension
-  ReadRegStr ${EXT} HKLM ${REGKEY} fileExtension
-  StrCmp ${EXT} "" 0 HasExt
-    StrCpy ${EXT} "pl"
-  HasExt:
-  WriteINIStr $PLUGINSDIR\options.ini "Field 4" "State" ${EXT}  
-
-# Startmenu program group
-  ReadRegStr ${GRP} HKLM ${REGKEY} group
-  StrCmp ${GRP} "" 0 HasGroup
-    StrCpy ${GRP} "YAP64"
-  HasGroup:
-  WriteINIStr $PLUGINSDIR\options.ini "Field 6" "State" ${GRP}  
-
-# Start the dialog
-  Push ${TEMP1}
-  InstallOptions::dialog "$PLUGINSDIR\options.ini"
-  Pop ${TEMP1}
-  Pop ${TEMP1}
-
-# Get the results
-  ReadINIStr ${EXT} $PLUGINSDIR\options.ini "Field 4" "State"
-  ReadINIStr ${GRP} $PLUGINSDIR\options.ini "Field 6" "State"
-FunctionEnd
-
-Function UserInfo
-  ClearErrors
-  UserInfo::GetName
-  IfErrors Win9x
-  Pop $0
-  UserInfo::GetAccountType
-  Pop $1
-
-  StrCmp $1 "Admin" 0 +4
-    SetShellVarContext all
-    StrCpy ${SHCTX} "all"
-    Goto done
-  StrCmp $1 "Power" 0 +3
-    StrCpy ${SHCTX} "all"
-    Goto done
-  StrCmp $1 "User" 0 +3
-    StrCpy ${SHCTX} "current"
-    Goto done
-  StrCmp $1 "Guest" 0 +3
-    StrCpy ${SHCTX} "current"
-    Goto done
-  StrCpy ${SHCTX} "current"		# Unkown accounttype
-    Goto done
-
-  Win9x:
-    StrCpy ${SHCTX}  "current"
-    Goto end
-
-  done:
-    StrCmp ${SHCTX} "all" 0 +2
-      SetShellVarContext all
-
-  end:
-FunctionEnd
-
-Function .onInstSuccess
-  MessageBox MB_YESNO "Installation complete. View readme?" IDNO NoReadme
-  ExecShell "open" "$INSTDIR\doc\README.TXT"
-  NoReadme:
-FunctionEnd
-
-Function .onInstFailed
-  MessageBox MB_OK "Installation failed.$\r$\n\
-		    If you cannot resolve the issue or it is a bug in the$\r$\n\
-		    installer, please contact yap-users@sf.net"
-FunctionEnd
-
-outfile "yap64-6.3.4-installer.exe"