diff --git a/libisoburn/trunk/Makefile.am b/libisoburn/trunk/Makefile.am
index 6ec4065f..e348bcc9 100644
--- a/libisoburn/trunk/Makefile.am
+++ b/libisoburn/trunk/Makefile.am
@@ -52,7 +52,7 @@ bin_PROGRAMS = \
 xorriso_xorriso_CPPFLAGS = -Ilibisoburn
 xorriso_xorriso_CFLAGS = -DXorriso_with_maiN \
                          $(READLINE_DEF) $(LIBACL_DEF) $(XATTR_DEF) \
-                         $(EXTF_DEF) $(EXTF_SUID_DEF)
+                         $(EXTF_DEF) $(EXTF_SUID_DEF) $(ZLIB_DEF)
 
 xorriso_xorriso_LDADD = libisoburn/libisoburn.la -lisofs -lburn \
 		$(THREAD_LIBS) $(LIBBURN_ARCH_LIBS)
diff --git a/libisoburn/trunk/configure.ac b/libisoburn/trunk/configure.ac
index 100a5acf..5bee7abf 100644
--- a/libisoburn/trunk/configure.ac
+++ b/libisoburn/trunk/configure.ac
@@ -145,6 +145,25 @@ fi
 AC_SUBST(XATTR_DEF)
 
 
+dnl ts A90409
+dnl Same situation as with xattr and ACL: libisoburn does not depend directly
+dnl on zlib. But if it is enabled in libisofs then it seems wise to link it
+dnl with libisoburn apps.
+AC_ARG_ENABLE(zlib,
+[  --enable-zlib     Enable use of zlib by libisofs, default=yes],
+               , enable_zlib=yes)
+if test x$enable_zlib = xyes; then
+dnl Check whether there is the header for zlib. 
+dnl If not, erase this macro which would enable use of compress2() and others.
+dnl The empty parameter after "compress2" causes -lz.
+    ZLIB_DEF="-DLibisofs_with_zliB"
+    AC_CHECK_HEADER(zlib.h, AC_CHECK_LIB(z, compress2, , ZLIB_DEF= ), ZLIB_DEF= )
+else
+    ZLIB_DEF=
+fi
+AC_SUBST(ZLIB_DEF)
+
+
 AC_ARG_ENABLE(external-filters,
 [  --enable-external-filters     Enable use of external filter programs by xorriso, default=yes],
                , enable_external_filters=yes)
diff --git a/libisoburn/trunk/xorriso/compile_xorriso.sh b/libisoburn/trunk/xorriso/compile_xorriso.sh
index 9386bfa8..b95c0afe 100755
--- a/libisoburn/trunk/xorriso/compile_xorriso.sh
+++ b/libisoburn/trunk/xorriso/compile_xorriso.sh
@@ -1,12 +1,13 @@
 #!/bin/sh
 
 # compile_xorriso.sh
-# Copyright 2005 - 2009 Thomas Schmitt, scdbackup@gmx.net, GPL
+# Copyright 2005 - 2009 Thomas Schmitt, scdbackup@gmx.net, GPL version 2
 #
 # Not intended for general use in production installations !
 # Rather use:  ./bootstrap ; ./configure ; make
 #
-# This is a development tool which expects a special setup of directories.
+# This is a development tool which expects a special setup of directories
+# on a Linux system (e.g. SuSE 10.2).
 # It is to be executed in a common parent of the directories given with
 #   $isofs $isoburn $burn $xorr
 
@@ -88,6 +89,7 @@ libisofs="$libisofs $isofs"make_isohybrid_mbr.o
 libisofs="$libisofs $isofs"aaip_0_2.o
 libisofs="$libisofs $isofs"filter.o
 libisofs="$libisofs $isofs_filter"external.o
+libisofs="$libisofs $isofs_filter"zisofs.o
 
 echo "Version timestamp :  $(sed -e 's/#define Xorriso_timestamP "//' -e 's/"$//' "$xorr"/xorriso_timestamp.h)"
 
@@ -145,7 +147,8 @@ cc -I. -DXorriso_with_maiN $def_libreadline \
   $link_libreadline \
   \
   -lpthread \
-  -lacl
+  -lacl \
+  -lz
 
   ret=$?
   if test "$ret" = 0
diff --git a/libisoburn/trunk/xorriso/configure_ac.txt b/libisoburn/trunk/xorriso/configure_ac.txt
index 79ea5f6e..20d21a20 100644
--- a/libisoburn/trunk/xorriso/configure_ac.txt
+++ b/libisoburn/trunk/xorriso/configure_ac.txt
@@ -156,6 +156,21 @@ fi
 AC_SUBST(XATTR_DEF)
 
 
+AC_ARG_ENABLE(zlib,
+[  --enable-zlib     Enable use of zlib by libisofs, default=yes],
+               , enable_zlib=yes)
+if test x$enable_zlib = xyes; then
+dnl Check whether there is the header for zlib.
+dnl If not, erase this macro which would enable use of compress2() and others.
+dnl The empty parameter after "compress2" causes -lz.
+    ZLIB_DEF="-DLibisofs_with_zliB"
+    AC_CHECK_HEADER(zlib.h, AC_CHECK_LIB(z, compress2, , ZLIB_DEF= ), ZLIB_DEF= )
+else
+    ZLIB_DEF=
+fi
+AC_SUBST(ZLIB_DEF)
+
+
 AC_ARG_ENABLE(external-filters,
 [  --enable-external-filters     Enable use of external filter programs by xorriso, default=yes],
                , enable_external_filters=yes)
diff --git a/libisoburn/trunk/xorriso/xorriso_makefile_am.txt b/libisoburn/trunk/xorriso/xorriso_makefile_am.txt
index e054a5f4..3082b3fe 100644
--- a/libisoburn/trunk/xorriso/xorriso_makefile_am.txt
+++ b/libisoburn/trunk/xorriso/xorriso_makefile_am.txt
@@ -22,7 +22,7 @@ xorriso_xorriso_CPPFLAGS = -I./libburn -I./libisofs -I./libisoburn -I./xorriso
 # are in a separate readline-development package.
 xorriso_xorriso_CFLAGS = -DXorriso_standalonE -DXorriso_with_maiN \
                          $(READLINE_DEF) $(LIBACL_DEF) $(XATTR_DEF) \
-                         $(EXTF_DEF) $(EXTF_SUID_DEF)
+                         $(EXTF_DEF) $(EXTF_SUID_DEF) $(ZLIB_DEF)
 
 xorriso_xorriso_LDADD = $(THREAD_LIBS) $(LIBBURN_ARCH_LIBS)
 
@@ -102,6 +102,7 @@ xorriso_xorriso_SOURCES = \
         libisofs/filter.h \
         libisofs/filter.c \
         libisofs/filters/external.c \
+        libisofs/filters/zisofs.c \
         libisofs/system_area.h \
         libisofs/system_area.c \
         libisofs/make_isohybrid_mbr.c \
diff --git a/libisoburn/trunk/xorriso/xorriso_timestamp.h b/libisoburn/trunk/xorriso/xorriso_timestamp.h
index 8feda6cf..d581ab31 100644
--- a/libisoburn/trunk/xorriso/xorriso_timestamp.h
+++ b/libisoburn/trunk/xorriso/xorriso_timestamp.h
@@ -1 +1 @@
-#define Xorriso_timestamP "2009.04.07.122117"
+#define Xorriso_timestamP "2009.04.10.102558"