diff --git a/development/unifdef/README b/development/unifdef/README
new file mode 100644
index 0000000000..c233377f98
--- /dev/null
+++ b/development/unifdef/README
@@ -0,0 +1,13 @@
+unifdef (selectively processes C conditional compilation)
+
+The unifdef utility selectively processes conditional C preprocessor #if
+and #ifdef directives. It removes from a file both the directives and the
+additional text that they delimit, while otherwise leaving the file alone.
+
+It is useful for avoiding distractions when studying code that uses
+#ifdef heavily for portability: the author's original motivation was to
+understand xterm's pty handling code. It can be used as a lightweight
+preprocessor; for example the Linux kernel uses unifdef to strip out
+#ifdef __KERNEL__ sections from the headers it exports to userland. You
+can use unifdef with languages other than C; for example UIT, a publisher
+in Cambridge, uses unifdef with LaTeX.
diff --git a/development/unifdef/slack-desc b/development/unifdef/slack-desc
new file mode 100644
index 0000000000..a2f5a978ca
--- /dev/null
+++ b/development/unifdef/slack-desc
@@ -0,0 +1,19 @@
+# HOW TO EDIT THIS FILE:
+# The "handy ruler" below makes it easier to edit a package description.
+# Line up the first '|' above the ':' following the base package name, and
+# the '|' on the right side marks the last column you can put a character in.
+# You must make exactly 11 lines for the formatting to be correct.  It's also
+# customary to leave one space after the ':' except on otherwise blank lines.
+
+       |-----handy-ruler------------------------------------------------------|
+unifdef: unifdef (selectively processes C conditional compilation)
+unifdef:
+unifdef: The unifdef utility selectively processes conditional C preprocessor
+unifdef: #if and #ifdef directives. It removes from a file both the directives
+unifdef: and the additional text that they delimit, while otherwise leaving
+unifdef: the file alone.
+unifdef:
+unifdef:
+unifdef:
+unifdef:
+unifdef:
diff --git a/development/unifdef/unifdef.SlackBuild b/development/unifdef/unifdef.SlackBuild
new file mode 100644
index 0000000000..e47137cd72
--- /dev/null
+++ b/development/unifdef/unifdef.SlackBuild
@@ -0,0 +1,75 @@
+#!/bin/sh
+
+# Slackware build script for unifdef
+
+# Written by B. Watson (yalhcru@gmail.com)
+
+# Licensed under the WTFPL. See http://www.wtfpl.net/txt/copying/ for details.
+
+PRGNAM=unifdef
+VERSION=${VERSION:-2.10}
+BUILD=${BUILD:-1}
+TAG=${TAG:-_SBo}
+
+if [ -z "$ARCH" ]; then
+  case "$( uname -m )" in
+    i?86) ARCH=i486 ;;
+    arm*) ARCH=arm ;;
+       *) ARCH=$( uname -m ) ;;
+  esac
+fi
+
+CWD=$(pwd)
+TMP=${TMP:-/tmp/SBo}
+PKG=$TMP/package-$PRGNAM
+OUTPUT=${OUTPUT:-/tmp}
+
+if [ "$ARCH" = "i486" ]; then
+  SLKCFLAGS="-O2 -march=i486 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "i686" ]; then
+  SLKCFLAGS="-O2 -march=i686 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "x86_64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
+else
+  SLKCFLAGS="-O2"
+  LIBDIRSUFFIX=""
+fi
+
+set -e
+
+rm -rf $PKG
+mkdir -p $TMP $PKG $OUTPUT
+cd $TMP
+rm -rf $PRGNAM-$VERSION
+tar xvf $CWD/$PRGNAM-$VERSION.tar.xz
+cd $PRGNAM-$VERSION
+chown -R root:root .
+find -L . \
+ \( -perm 777 -o -perm 775 -o -perm 750 -o -perm 711 -o -perm 555 \
+  -o -perm 511 \) -exec chmod 755 {} \; -o \
+ \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
+ -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
+
+make CFLAGS="$SLKCFLAGS" DESTDIR=$PKG
+
+mkdir -p $PKG/usr/bin $PKG/usr/man/man1
+
+# manual install = less code than hacking 'make install'
+install -s -m0755 $PRGNAM $PKG/usr/bin
+install -m0755 ${PRGNAM}all.sh $PKG/usr/bin/${PRGNAM}all
+gzip -9c < $PRGNAM.1 > $PKG/usr/man/man1/$PRGNAM.1.gz
+ln -s $PRGNAM.1.gz $PKG/usr/man/man1/${PRGNAM}all.1.gz
+
+mkdir -p $PKG/usr/doc/$PRGNAM-$VERSION
+gzip -9 Changelog # it's bloody enormous
+cp -a COPYING README Changelog.gz $PKG/usr/doc/$PRGNAM-$VERSION
+cat $CWD/$PRGNAM.SlackBuild > $PKG/usr/doc/$PRGNAM-$VERSION/$PRGNAM.SlackBuild
+
+mkdir -p $PKG/install
+cat $CWD/slack-desc > $PKG/install/slack-desc
+
+cd $PKG
+/sbin/makepkg -l y -c n $OUTPUT/$PRGNAM-$VERSION-$ARCH-$BUILD$TAG.${PKGTYPE:-tgz}
diff --git a/development/unifdef/unifdef.info b/development/unifdef/unifdef.info
new file mode 100644
index 0000000000..baad8faef7
--- /dev/null
+++ b/development/unifdef/unifdef.info
@@ -0,0 +1,10 @@
+PRGNAM="unifdef"
+VERSION="2.10"
+HOMEPAGE="http://dotat.at/prog/unifdef/"
+DOWNLOAD="http://dotat.at/prog/unifdef/unifdef-2.10.tar.xz"
+MD5SUM="bb5d895e5ebbba5c5cc0c2771cf97ebe"
+DOWNLOAD_x86_64=""
+MD5SUM_x86_64=""
+REQUIRES=""
+MAINTAINER="B. Watson"
+EMAIL="yalhcru@gmail.com"