diff --git a/.gitignore b/.gitignore
index 385f871..d7c388c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 tmp/
 kernel
+sources/
diff --git a/.gitmodules b/.gitmodules
index dcb71ab..e91e301 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -22,6 +22,6 @@
 [submodule "sysa/tcc-0.9.27"]
 	path = sysa/tcc-0.9.27
 	url = git://repo.or.cz/tinycc.git
-[submodule "sysa/sed-1.18"]
-	path = sysa/sed-1.18
-	url = git://git.savannah.gnu.org/sed/sed-history.git
+[submodule "sysa/sed-4.0.7"]
+	path = sysa/sed-4.0.7
+	url = https://git.savannah.gnu.org/git/sed/sed-history.git
diff --git a/rootfs.sh b/rootfs.sh
index 09007c8..5045c9c 100755
--- a/rootfs.sh
+++ b/rootfs.sh
@@ -75,9 +75,36 @@ popd
 
 mkdir -p ../sources
 
-# sed 1.18
-cp sed-1.18.kaem tmp/after
-cp -r sed-1.18 tmp/after
+# sed 4.0.7
+cp sed-4.0.7.kaem tmp/after
+cp -r sed-4.0.7 tmp/after
+
+# tar 1.12
+url=https://ftp.gnu.org/gnu/tar/tar-1.12.tar.gz
+pushd ../sources
+wget --continue "$url"
+popd
+cp "$(basename $url .tar.gz).kaem" tmp/after
+tar -C tmp/after -xf "../sources/$(basename $url)"
+
+get_file() {
+    url=$1
+    pushd ../sources
+    wget --continue "$url"
+    popd
+    ext="${url##*.}"
+    if [ "$ext" = "tar" ]; then
+	bname=$(basename "$url" .tar)
+    else
+	bname=$(basename "$url" ".tar.${ext}")
+    fi
+    cp "${bname}.kaem" tmp/after
+    cp "../sources/$(basename "$url")" tmp/after
+}
+
+# Download remaining sources
+get_file https://ftp.gnu.org/gnu/gzip/gzip-1.2.4.tar
+get_file https://ftp.gnu.org/gnu/diffutils/diffutils-2.7.tar.gz
 
 # General cleanup
 find tmp -name .git -exec rm -rf \;
@@ -88,7 +115,7 @@ find . | cpio -H newc -o | gzip > initramfs.igz
 
 # Run
 ${QEMU_CMD:-qemu-system-x86_64} -enable-kvm \
-    -m ${RAM:-8G} \
+    -m "${RAM:-8G}" \
     -nographic \
     -no-reboot \
     -kernel ../../kernel -initrd initramfs.igz -append console=ttyS0
diff --git a/sysa/after.kaem.run b/sysa/after.kaem.run
index 9c80b03..944e177 100755
--- a/sysa/after.kaem.run
+++ b/sysa/after.kaem.run
@@ -49,6 +49,24 @@ kaem --file mes.kaem
 kaem --file tcc.kaem
 
 # Part 7: sed
-cd sed-1.18
-kaem --file ../sed-1.18.kaem
+cd sed-4.0.7
+kaem --file ../sed-4.0.7.kaem
+cd ..
+
+# Part 8: tar
+cd tar-1.12
+kaem --file ../tar-1.12.kaem
+cd ..
+
+# Part 9: gzip
+/after/bin/tar xf gzip-1.2.4.tar
+cd gzip-1.2.4
+kaem --file ../gzip-1.2.4.kaem
+cd ..
+
+# Part 10: diffutils
+/after/bin/gunzip diffutils-2.7.tar.gz
+/after/bin/tar xf diffutils-2.7.tar
+cd diffutils-2.7
+kaem --file ../diffutils-2.7.kaem
 cd ..
diff --git a/sysa/diffutils-2.7.kaem b/sysa/diffutils-2.7.kaem
new file mode 100755
index 0000000..ed8ac10
--- /dev/null
+++ b/sysa/diffutils-2.7.kaem
@@ -0,0 +1,34 @@
+#!/bin/sh
+
+set -ex
+
+# Variables
+bindir=/after/bin
+
+# Touch config.h file
+catm config.h
+
+# Compile
+tcc -c -I. -DNULL_DEVICE=\"/dev/null\" cmp.c
+tcc -c -I. cmpbuf.c
+tcc -c -I. error.c
+tcc -c -I. getopt.c
+tcc -c -I. getopt1.c
+tcc -c -I. xmalloc.c
+tcc -c -I. version.c
+tcc -c -I. diff.c
+tcc -c -I. analyze.c
+tcc -c -I. -DHAVE_DIRENT_H dir.c
+tcc -c -I. io.c
+tcc -c -I. -DHAVE_DUP2 -DHAVE_FORK=0 util.c
+tcc -c -I. context.c
+tcc -c -I. ed.c
+tcc -c -I. ifdef.c
+tcc -c -I. normal.c
+tcc -c -I. side.c
+tcc -c -I. fnmatch.c
+tcc -c -I. regex.c
+
+# Link
+tcc -static -o ${bindir}/cmp cmp.o cmpbuf.o error.o getopt.o getopt1.o xmalloc.o version.o
+tcc -static -o ${bindir}/diff diff.o analyze.o cmpbuf.o dir.o io.o util.o context.o ed.o ifdef.o normal.o side.o fnmatch.o getopt.o getopt1.o regex.o version.o
diff --git a/sysa/gzip-1.2.4.kaem b/sysa/gzip-1.2.4.kaem
new file mode 100755
index 0000000..3aa58dc
--- /dev/null
+++ b/sysa/gzip-1.2.4.kaem
@@ -0,0 +1,34 @@
+#!/bin/sh
+
+set -ex
+
+# Variables
+bindir=/after/bin
+
+# Compile
+tcc -c -DNO_UTIME gzip.c
+tcc -c bits.c
+tcc -c crypt.c
+tcc -c deflate.c
+tcc -c getopt.c
+tcc -c inflate.c
+tcc -c lzw.c
+tcc -c trees.c
+tcc -c unlzh.c
+tcc -c unlzw.c
+tcc -c unpack.c
+tcc -c unzip.c
+# Remove strlwr, it does not build with mes libc
+cp util.c util_patched.c
+sed -i 165,174d util_patched.c
+tcc -c util_patched.c
+tcc -c zip.c
+
+# Link
+tcc -static -o ${bindir}/gzip gzip.o zip.o deflate.o trees.o bits.o unzip.o inflate.o util_patched.o crypt.o lzw.o unlzw.o unpack.o unlzh.o getopt.o
+
+# Install
+cp ${bindir}/gzip ${bindir}/gunzip
+cp ${bindir}/gzip ${bindir}/zcat
+chmod 755 ${bindir}/gunzip
+chmod 755 ${bindir}/zcat
diff --git a/sysa/sed-1.18 b/sysa/sed-1.18
deleted file mode 160000
index cff4df5..0000000
--- a/sysa/sed-1.18
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit cff4df55786bae5f4f0c042a13d30cd1a962040c
diff --git a/sysa/sed-1.18.kaem b/sysa/sed-1.18.kaem
deleted file mode 100755
index 43596da..0000000
--- a/sysa/sed-1.18.kaem
+++ /dev/null
@@ -1,17 +0,0 @@
-#!/bin/sh
-
-set -ex
-
-# Variables
-bindir=/after/bin
-
-# Compile
-tcc -c getopt1.c
-tcc -c getopt.c
-tcc -c regex.c
-tcc -c utils.c
-tcc -c -Dalloca alloca.c
-tcc -c -DHAVE_BCOPY sed.c
-
-# Link
-tcc -static -o ${bindir}/sed alloca.o getopt1.o getopt.o regex.o sed.o utils.o
diff --git a/sysa/sed-4.0.7 b/sysa/sed-4.0.7
new file mode 160000
index 0000000..b8fb156
--- /dev/null
+++ b/sysa/sed-4.0.7
@@ -0,0 +1 @@
+Subproject commit b8fb156db0eedfd28db3340b418591e8fcab08bc
diff --git a/sysa/sed-4.0.7.kaem b/sysa/sed-4.0.7.kaem
new file mode 100755
index 0000000..dade234
--- /dev/null
+++ b/sysa/sed-4.0.7.kaem
@@ -0,0 +1,37 @@
+#!/bin/sh
+
+set -ex
+
+# Variables
+bindir=/after/bin
+
+catm config.h
+
+# Compile
+
+## libsed.a
+cd lib
+
+tcc -c getopt1.c
+tcc -c -I .. getopt.c
+tcc -c -I .. -DENABLE_NLS=0 utils.c
+cp regex_.h regex.h
+tcc -c -I . regex.c
+tcc -c obstack.c
+tcc -c strverscmp.c
+tcc -c getline.c
+tcc -c -DHAVE_FCNTL_H mkstemp.c
+
+tcc -ar cr libsed.a getopt1.o getopt.o utils.o regex.o obstack.o strverscmp.o getline.o mkstemp.o
+cd ..
+
+## sed
+tcc -c -I . -I lib -DSED_FEATURE_VERSION=\"4.0\" sed/compile.c
+tcc -c -I . -I lib sed/execute.c
+tcc -c -I . -I lib sed/regex.c
+tcc -c -I . -I lib sed/fmt.c
+tcc -c -I . -I lib -DPACKAGE=\"sed\" -DVERSION=\"4.0.7\" sed/sed.c
+
+# Link
+tcc -static -o ${bindir}/sed -L lib lib/libsed.a compile.o execute.o regex.o fmt.o sed.o -lsed
+
diff --git a/sysa/tar-1.12.kaem b/sysa/tar-1.12.kaem
new file mode 100755
index 0000000..f038f0d
--- /dev/null
+++ b/sysa/tar-1.12.kaem
@@ -0,0 +1,51 @@
+#!/bin/sh
+
+set -ex
+
+# Variables
+bindir=/after/bin
+
+# Compile
+
+## libtar.a
+cd lib
+
+tcc -c argmatch.c
+tcc -c -DHAVE_DIRENT_H backupfile.c
+tcc -c -I . error.c
+tcc -c -I . fnmatch.c
+tcc -c ftruncate.c
+tcc -c getdate.c
+tcc -c getopt.c
+tcc -c getopt1.c
+tcc -c getversion.c
+tcc -c modechange.c
+tcc -c msleep.c
+tcc -c -DHAVE_GETCWD xgetcwd.c
+tcc -c xmalloc.c
+tcc -c xstrdup.c
+
+tcc -ar cr libtar.a argmatch.o backupfile.o error.o fnmatch.o ftruncate.o getdate.o getopt.o getopt1.o getversion.o modechange.o msleep.o xgetcwd.o xmalloc.o xstrdup.o
+cd ..
+
+## tar
+# -DSIZEOF_UNSIGNED_LONG=4 forces use of simulated arithmetic
+# This is to avoid running configure test to determine sizeof(long long)
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/arith.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/buffer.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/compare.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H -DHAVE_DIRENT_H src/create.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/delete.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/extract.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H -DHAVE_GETCWD -DHAVE_DIRENT_H src/incremen.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/list.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/mangle.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H -DHAVE_DIRENT_H src/misc.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H -DHAVE_GETCWD src/names.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/open3.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/rtapelib.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H -DPACKAGE=\"tar\" -DVERSION=\"1.12\" src/tar.c
+tcc -c -I lib -DSIZEOF_UNSIGNED_LONG=4 -DHAVE_FCNTL_H src/update.c
+
+# Link
+tcc -static -o ${bindir}/tar -L lib lib/libtar.a arith.o buffer.o compare.o create.o delete.o extract.o incremen.o list.o mangle.o misc.o names.o open3.o rtapelib.o tar.o update.o -ltar