diff --git a/geant/files/geant-4.9.1_p01-configure.patch b/geant/files/geant-4.9.1_p01-configure.patch
deleted file mode 100644
index 55c925d..0000000
--- a/geant/files/geant-4.9.1_p01-configure.patch
+++ /dev/null
@@ -1,116 +0,0 @@
---- Configure.orig	2007-11-28 13:49:23.000000000 +0000
-+++ Configure	2008-04-07 18:45:41.317949330 +0000
-@@ -579,16 +579,17 @@
- 	;;
- esac
- 
--: Sanity checks
--case "$fastread$alldone" in
--yescont|yesexit) ;;
--*)
--	if test ! -t 0; then
--		echo "Say 'sh Configure', not 'sh <Configure'"
--		exit 1
--	fi
--	;;
--esac
-+# breaks things in a sandbox.
-+# : Sanity checks
-+# case "$fastread$alldone" in
-+# yescont|yesexit) ;;
-+# *)
-+# 	if test ! -t 0; then
-+# 		echo "Say 'sh Configure', not 'sh <Configure'"
-+# 		exit 1
-+# 	fi
-+# 	;;
-+# esac
- 
- exec 4>&1
- case "$silent" in
-@@ -982,7 +983,7 @@
- : general instructions
- needman=true
- firsttime=true
--user=`(logname) 2>/dev/null`
-+user=`(logname || true) 2>/dev/null`
- case "$user" in
- '') user=`whoami 2>&1`;;
- esac
-@@ -1315,7 +1316,6 @@
- '')
- myuname=`( ($uname -a) 2>/dev/null || hostname) 2>&1`
- 
--mygcc=`( ($g++ -v) 2>/dev/null) 2>&1`
- myuname=`echo $myuname | $sed -e 's/^[^=]*=//' -e 's/\///g' | \
- 	./tr '[A-Z]' '[a-z]' | tr '\012' ' '`
- newmyuname="$myuname"
-@@ -1911,7 +1911,7 @@
- 	
- 	. $src/.config/bin/$g4system/move.sh
- 
--	exit 1
-+	exit 0
- 
- 	fi #end of cppflags
- 
-@@ -2119,7 +2119,7 @@
- cp -i $src/.config/bin/$g4system/env.csh .
- cp -i $src/.config/bin/$g4system/env.sh  .
- 
--	exit 1
-+	exit 0
- 	fi #end of -lib or user
- else #there is no env.sh
- 
-@@ -2217,7 +2217,7 @@
- 
- : who configured the system
- cf_time=`$date 2>&1`
--cf_by=`(logname) 2>/dev/null`
-+cf_by=`(logname || true) 2>/dev/null`
- case "$cf_by" in
- "")
- 	cf_by=`(whoami) 2>/dev/null`
-@@ -4200,9 +4200,9 @@
- if test "X$g4osname" = "XLinux" ; then
- g4vis_xmflags=" -I$g4vis_xmhome/include "
- 	if test "X$g4vis_xmhome" = "X/usr/X11R6" ; then
--		g4vis_xmlibs=" -lXm -lXpm "
-+		g4vis_xmlibs=" -lXm "
- 	else
--		g4vis_xmlibs=" -L$g4vis_xmhome/lib -lXm -lXpm "
-+		g4vis_xmlibs=" -L$g4vis_xmhome/lib -lXm "
- 	fi
- fi
- 
-@@ -4908,9 +4908,9 @@
- if test "X$g4osname" = "XLinux" ; then
- g4vis_xmflags=" -I$g4vis_xmhome/include "
- 	if test "X$g4vis_xmhome" = "X/usr/X11R6" ; then
--		g4vis_xmlibs=" -lXm -lXpm "
-+		g4vis_xmlibs=" -lXm "
- 	else
--		g4vis_xmlibs=" -L$g4vis_xmhome/lib -lXm -lXpm "
-+		g4vis_xmlibs=" -L$g4vis_xmhome/lib -lXm "
- 	fi
- fi
- 
-@@ -6123,7 +6123,7 @@
- 
- echo ""
- 
--	g4_gmake_version=`(gmake -v) 2>/dev/null` 
-+	g4_gmake_version=`(gmake -v || true) 2>/dev/null` 
- 				case $g4_gmake_version in
- 				GNU*) 
- 				g4_gmake=y				
-@@ -6133,7 +6133,7 @@
- 				;;
- 				esac				
- 
--	g4_make_version=`(make -v) 2>/dev/null`
-+	g4_make_version=`(make -v || true) 2>/dev/null`
- 				case $g4_make_version in
- 				GNU*) 
- 				g4_make=y				
diff --git a/geant/files/geant-4.9.1_p01-no-source.patch b/geant/files/geant-4.9.1_p01-no-source.patch
deleted file mode 100644
index add9da4..0000000
--- a/geant/files/geant-4.9.1_p01-no-source.patch
+++ /dev/null
@@ -1,45 +0,0 @@
---- config/scripts/move.sh.SH.orig	2008-04-08 16:08:16.817366051 +0000
-+++ config/scripts/move.sh.SH	2008-04-10 15:21:09.507532565 +0000
-@@ -445,39 +445,14 @@
- cd $g4install
- #echo `pwd`
- 
--
--# Remove 'verbosity' in 'tar' command
--# If not INCLUDE then install full tree in 'src' directory!
--#
--if [ X$g4includes_flag = Xn ] ; then
--if [ X$g4install != X$g4final_install ] ; then
--echo ""
--echo "Installing sources and headers..."
--echo ""
--mkdir -p $g4final_install/src/geant4/
--tar cf - Configure config/ source/ environments/ examples/ include/ |(cd $g4final_install/src/geant4/; tar xf -)
--fi
--fi
--
--########################################
--# There is no env!
--if [ X$g4includes_flag = Xy ] ; then
--
--if [ X$g4install != X$g4final_install ] ; then
--echo ""
--echo "Installing sources..."
--echo ""
--
--mkdir -p $g4final_install/src/geant4/
--tar cf - Configure config/ source/ environments/ examples/ |(cd $g4final_install/src/geant4/; tar xf -)
--fi
--
-+# Remove all the stuff to not install sources
-+# 
- echo ""
- echo "Installing headers..."
- echo ""
- cd $g4install/source
- $g4make includes dependencies=""
--fi
-+
- 
- # Move libraries
- if [ X$g4install != X$g4final_install ] ; then
diff --git a/geant/geant-4.9.1_p01.ebuild b/geant/geant-4.9.1_p01.ebuild
index fef365e..72f9db8 100644
--- a/geant/geant-4.9.1_p01.ebuild
+++ b/geant/geant-4.9.1_p01.ebuild
@@ -4,12 +4,12 @@
 
 EAPI="1"
 
-inherit eutils fortran multilib versionator
+inherit eutils fortran multilib versionator toolchain-funcs
 
 MY_P=${PN}$(replace_version_separator 3 .)
 
 DESCRIPTION="CERN's detector description and simulation Tool"
-HOMEPAGE="http://geant4.cern.ch/"
+HOMEPAGE="http://www.geant4.org/"
 
 SRC_COM="http://geant4.web.cern.ch/geant4/support/source/"
 SRC_URI="${SRC_COM}/${MY_P}.tar.gz"
@@ -44,142 +44,141 @@ S="${WORKDIR}/${MY_P}"
 pkg_setup() {
 	FORTRAN="gfortran g77 ifc"
 	use geant3 && fortran_pkg_setup
+	eval unset ${!G4_*}
 }
 
 src_unpack() {
 	unpack ${A}
 	cd "${S}"
 
-	# this patch sanitize the Configure script
-	epatch "${FILESDIR}"/${P}-configure.patch
-	epatch "${FILESDIR}"/${P}-no-source.patch
-
-	# propagate user's make options
-	sed -i \
-		-e "s/g4make=gmake/g4make=\"gmake ${MAKEOPTS}\"/" \
-		Configure || die "sed Configure failed"
-
+	# TODO is this still needed? We are using emake below ...
 	# propagate user's flags.
 	sed -i \
 		-e "s:\(CXXFLAGS*+=\)*-O2:\1 ${CXXFLAGS:--O2}:g" \
 		-e "s:\(FCFLAGS*+=\)*-O2:\1 ${FFLAGS:--O2}:g" \
 		-e "s:\(CCFLAGS*+=\)*-O2:\1 ${CFLAGS:--O2}:g" \
 		config/sys/Linux* || die "flag substitution failed"
-
-	# libdir stuff
-	sed -i \
-		-e "s:lib/geant4:$(get_libdir)/geant:g" \
-		Configure config/scripts/move.sh.SH \
-		|| die "multilib substitution failed"
-}
-
-g4ui_use() {
-	local answer=$(use $1 && echo y || echo n)
-	echo "-D g4ui_build_${2:-$1}_session=${answer}
-		  -D g4ui_use_${2:-$1}=${answer}"
-}
-
-g4vis_use() {
-	local answer=$(use $1 && echo y || echo n)
-	echo "-D g4vis_build_${2:-$1}_driver=${answer}
-		  -D g4vis_use_${2:-$1}=${answer}"
-}
-
-g4w_use() {
-	local answer=$(use $1 && echo y || echo n)
-	echo "-D g4w_use_${2:-$1}=${answer}
-		  -D g4wlib_use_${2:-$1}=${answer}"
 }
 
 src_compile() {
-
-	GEANT4_DIR=/usr/share/${PN}-${SLOT}
-	GEANT4_DATA_DIR=${GEANT4_DIR}/data
-
-	# The Configure shell script saves its options
-	# in .config/bin/*/config.sh
-	local myconf="$(g4vis_use opengl openglx)"
-	use opengl && myconf="${glconf} $(g4vis_use motif openglxm)"
-	use data && myconf="${myconf} -D g4data=${GEANT4_DATA_DIR}"
-
-	 # switch to see compiling flags
+	export GEANT4_DIR="/usr/share/${PN}-${SLOT}"
+
+	# these should always to be set
+	# TODO icc untested
+	[[ $(tc-getCXX) = ic*c ]] && export G4SYSTEM=Linux-icc \
+	                          || export G4SYSTEM=Linux-g++
+	export G4INSTALL="${S}"
+	export G4INCLUDE="${D}/usr/include/${PN}"
+	export CLHEP_BASE_DIR=/usr
+
+	# where to put compiled libraries;
+	# we set env var G4LIB in src_install()
+	# to avoid confusing make
+	export LIB_DIR_TMP="/usr/$(get_libdir)/${PN}"
+
+	# parse USE; just set flags of drivers to build, G4*_USE_* vars are set
+	# later automatically for G4*_BUILD_*_DRIVER
+	use minimal             && export G4UI_NONE=y \
+	                        && export G4VIS_NONE=y
+
+	use motif               && export G4UI_BUILD_XM_SESSION=y
+	use athena              && export G4UI_BUILD_XAW_SESSION=y
+
+	use dawn                && export G4VIS_BUILD_DAWN_DRIVER=y
+	use raytracerx          && export G4VIS_BUILD_RAYTRACERX_DRIVER=y
+	use openinventor        && export G4VIS_BUILD_OI_DRIVER=y
+	use opengl              && export G4VIS_BUILD_OPENGLX_DRIVER=y
+	use opengl && use motif && export G4VIS_BUILD_OPENGLXM_DRIVER=y
+
+	use geant3              && export G4LIB_BUILD_G3TOG4=y
+	use zlib                && export G4LIB_BUILD_ZLIB=y
+	use vrml                && export G4VIS_BUILD_VRML_DRIVER=y \
+	                        && export G4VIS_BUILD_VRMLFILE_DRIVER=y
+
+	use data                && export G4DATA="${GEANT4_DIR}/data"
+	use debug               && export G4DEBUG=y || export G4OPTIMIZE=y
+
+	# switch to see compiling flags
 	export CPPVERBOSE=y
-	use debug && export G4DEBUG=y || export G4OPTIMIZE=y
-
-	# to check what they are doing and working
-	# -D d_portable \
-	# -D g4global=n \
-	# -D g4granular=y
-	# -D g4_use_granular=y
-	# -D g4make=make \
-
-	./Configure \
-		-deE -build \
-		-D g4analysis_use=n \
-		-D g4includes_flag=y \
-		-D g4include="${D}/usr/include/geant4" \
-		-D g4final_install="${D}/usr" \
-		$(g4ui_use minimal none) \
-		$(g4ui_use athena xaw) \
-		$(g4ui_use motif xm) \
-		$(g4vis_use minimal none) \
-		$(g4vis_use dawn) \
-		$(g4vis_use raytracerx) \
-		$(g4vis_use openinventor oix) \
-		$(g4vis_use vrml) \
-		$(g4vis_use vrml vrmlfile) \
-		$(g4w_use geant3 g3tog4) \
-		$(g4w_use zlib) \
-		${myconf} \
-		${EXTRA_ECONF} \
-		|| die "Configure failed"
+
+	# internal variables of ./Configure
+	# -D d_portable \      # seems to be a local variable of ./Configure
+	# -D g4global=n \      # create few BIG global libraries
+	# -D g4granular=y      # create many small libraries for submodules (default)
+	# -D g4_use_granular=y # link against the BIG global library when compiling apps
+	# TODO if we really want GLOBAL libraries (too), we would use
+	# use global && emake global || die "Building global geant failed"
+	# and set G4LIB_USE_GRANULAR=y in env.*sh
 
 	# if shared libs are built, the script will also build static libs
 	# with pic flags
 	# avoid that by building it twice and removing temporary objects
-
-	./Configure \
-		-deO -build \
-		-D g4lib_build_shared=y \
-		-D g4lib_build_static=n \
-		|| die "Building shared geant failed"
+	cd "${S}/source/"
+	export G4LIB_BUILD_SHARED=y
+	emake || die "Building shared geant failed"
 
 	if use static; then
 		rm -rf tmp
-		./Configure \
-			-deO -build \
-			-D g4lib_build_shared=n \
-			-D g4lib_build_static=y \
-			|| die "Building shared geant failed"
+		export G4LIB_BUILD_STATIC=y ; unset G4LIB_BUILD_SHARED
+		emake || die "Building static geant failed"
 	fi
 }
 
+g4_create_env_scripts() {
+	# we need to change some variables to the final values since we hide these
+	# from make during the compile
+	export G4INSTALL="${GEANT4_DIR}"
+	export G4LIB="${LIB_DIR_TMP}"
+	export G4INCLUDE=`echo $G4INCLUDE | sed s:${D}::`
+
+	export G4WORKDIR="/tmp/geant4"/ # TODO howto set it to e.g. $HOME/geant4 ?
+	echo "export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:${G4LIB}" >> "env.sh"
+	echo "setenv LD_LIBRARY_PATH $LD_LIBRARY_PATH:${G4LIB}" >> "env.csh"
+	echo "export CLHEP_BASE_DIR=$CLHEP_BASE_DIR"            >> "env.sh"
+	echo "setenv CLHEP_BASE_DIR $CLHEP_BASE_DIR"            >> "env.csh"
+	# read env variables defined upto now
+	for v in `env | grep ^G4 | uniq`; do
+		echo "export $v"   >> "env.sh" # these are already set to "y"
+		echo "setenv $v y" >> "env.csh"
+	done
+	# define env vars for capabilities we can build into user projects
+	for v in `env | grep ^G4 | uniq | grep DRIVER | cut -d= -f1 | \
+		sed -e s~BUILD~USE~ -e s~_DRIVER~~`
+	do
+		echo "export $v=y" >> "env.sh"
+		echo "setenv $v y" >> "env.csh"
+	done
+}
+
 src_install() {
-	./Configure \
-		-install \
-		|| die "Install failed"
+	# install headers via make since we want them in a single directory
+	cd "${S}/source/"
+	emake includes || die 'Installing headers failed'
+	cd "${S}"
 
-	./Configure \
-		|| die "Final install failed"
+	# but install libraries and Geant library tool manually
+	insinto "${LIB_DIR_TMP}"
+	doins -r "lib/${G4SYSTEM}/"*
+	exeinto "${LIB_DIR_TMP}"
+	doexe "lib/${G4SYSTEM}/liblist"
 
-	# install env stuff
-	# todo: try to decipher and translate into a env.d file
+	# env scripts and configs
 	insinto ${GEANT4_DIR}
-	sed -i \
-		-e "s:${S}:${GEANT4_DIR}:g" \
-		-e "s:${D}:/:g" \
-		env.*sh
+	g4_create_env_scripts
 	doins env.*sh || die "failed installing shell scripts"
+	sed -i s~\$\(G4LIB\)/\$\(G4SYSTEM\)~\$\(G4LIB\)~g \
+		config/binmake.gmk || die "Adjusting paths failed"
 	doins -r config
 
 	# install data
-	insinto ${GEANT4_DATA_DIR}
 	if use data; then
+		insinto ${G4DATA}
 		cd "${WORKDIR}"
 		for d in ${GEANT4_DATA}; do
 			local p=${d/.}
 			doins -r *${p/G4} || die "installing data ${d} failed"
 		done
+		cd "${S}"
 	fi
 
 	# doc and examples
@@ -198,9 +197,9 @@ src_install() {
 
 pkg_postinst() {
 	elog "You can set the Geant4 environment variables"
-	elog "from ${ROOT}${GEANT4_DIR} shell scripts."
+	elog "from ${GEANT4_DIR} shell scripts."
 	elog "Ex: for bash"
-	elog "     source ${ROOT}${GEANT4_DIR}/env.sh"
+	elog "     source ${GEANT4_DIR}/env.sh"
 	elog
 	elog "Help us to improve the ebuild and dependencies in"
 	elog "http://bugs.gentoo.org/show_bug.cgi?id=212221"
diff --git a/geant/metadata.xml b/geant/metadata.xml
index 8dada07..256a42f 100644
--- a/geant/metadata.xml
+++ b/geant/metadata.xml
@@ -5,7 +5,8 @@
 <longdescription lang="en">
   Geant simulates the passage of subatomic particles through matter, for
   instance, particle detectors. For maximum flexibility, Geant
-  simulations are performed by linking Fortran code supplied by the user
+  simulations are performed by linking code supplied by the user
   with the Geant libraries, then running the resulting executable.
+  Geant-3.* was written in Fortran, while Geant-4.* is a rewrite in C++.
 </longdescription>
 </pkgmetadata>