diff --git a/office/BibTool/BibTool.SlackBuild b/office/BibTool/BibTool.SlackBuild
new file mode 100644
index 0000000000..bfac5d5a38
--- /dev/null
+++ b/office/BibTool/BibTool.SlackBuild
@@ -0,0 +1,117 @@
+#!/bin/bash
+
+# Slackware build script for BibTool
+
+# Copyright 2023, Alexander Verbovetsky, Moscow, Russia
+# All rights reserved.
+#
+# Redistribution and use of this script, with or without modification, is
+# permitted provided that the following conditions are met:
+#
+# 1. Redistributions of this script must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED
+#  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
+#  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO
+#  EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+#  SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+#  PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+#  OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+#  WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+#  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+#  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+cd $(dirname $0) ; CWD=$(pwd)
+
+PRGNAM=BibTool
+VERSION=${VERSION:-2.68}
+BUILD=${BUILD:-1}
+TAG=${TAG:-_SBo}
+PKGTYPE=${PKGTYPE:-tgz}
+
+if [ -z "$ARCH" ]; then
+  case "$( uname -m )" in
+    i?86) ARCH=i586 ;;
+    arm*) ARCH=arm ;;
+       *) ARCH=$( uname -m ) ;;
+  esac
+fi
+
+if [ ! -z "${PRINT_PACKAGE_NAME}" ]; then
+  echo "$PRGNAM-$VERSION-$ARCH-$BUILD$TAG.$PKGTYPE"
+  exit 0
+fi
+
+TMP=${TMP:-/tmp/SBo}
+PKG=$TMP/package-$PRGNAM
+OUTPUT=${OUTPUT:-/tmp}
+
+if [ "$ARCH" = "i586" ]; then
+  SLKCFLAGS="-O2 -march=i586 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "i686" ]; then
+  SLKCFLAGS="-O2 -march=i686 -mtune=i686"
+  LIBDIRSUFFIX=""
+elif [ "$ARCH" = "x86_64" ]; then
+  SLKCFLAGS="-O2 -fPIC"
+  LIBDIRSUFFIX="64"
+elif [ "$ARCH" = "aarch64" ]; 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
+tar xvf $CWD/$PRGNAM-$VERSION.tar.gz
+cd $PRGNAM
+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 {} \;
+
+patch -p1 < $CWD/c61cf667bdf846a2ad5079a8eae7fc863389f71b.patch
+
+sed -i -e "s|/usr/local/lib/BibTool|/usr/lib${LIBDIRSUFFIX}/BibTool|" \
+  doc/bibtool.1
+
+mkdir -p $PKG/usr/lib${LIBDIRSUFFIX}/$PRGNAM
+
+CFLAGS="$SLKCFLAGS" \
+CXXFLAGS="$SLKCFLAGS" \
+./configure \
+  --prefix=/usr \
+  --libdir=/usr/lib${LIBDIRSUFFIX} \
+  --mandir=/usr/man \
+  --build=$ARCH-slackware-linux
+
+make all doc
+make install INSTALLPREFIX=$PKG
+make install.man INSTALLPREFIX=$PKG INSTALL="install -p -m 644"
+
+rm -f $PKG/{,usr/}lib${LIBDIRSUFFIX}/*.la
+
+find $PKG -print0 | xargs -0 file | grep -e "executable" -e "shared object" | grep ELF \
+  | cut -f 1 -d : | xargs strip --strip-unneeded 2> /dev/null || true
+
+find $PKG/usr/man -type f -exec gzip -9 {} \;
+for i in $( find $PKG/usr/man -type l ) ; do ln -s $( readlink $i ).gz $i.gz ; rm $i ; done
+
+mkdir -p $PKG/usr/doc/$PRGNAM-$VERSION
+cp -a Changes.tex README.md THANKS ToDo doc/*.pdf $PKG/usr/doc/$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
diff --git a/office/BibTool/BibTool.info b/office/BibTool/BibTool.info
new file mode 100644
index 0000000000..71baf428e1
--- /dev/null
+++ b/office/BibTool/BibTool.info
@@ -0,0 +1,12 @@
+PRGNAM="BibTool"
+VERSION="2.68"
+HOMEPAGE="https://www.gerd-neugebauer.de/software/TeX/BibTool/en/"
+DOWNLOAD="https://www.gerd-neugebauer.de/software/TeX/BibTool/BibTool-2.68.tar.gz \
+          https://github.com/ge-ne/bibtool/commit/c61cf667bdf846a2ad5079a8eae7fc863389f71b.patch"
+MD5SUM="1fcf32fb26d8f7e79a56b531190c614c \
+        ac3c5c10038bfe3fd18f498526d7cd0d"
+DOWNLOAD_x86_64=""
+MD5SUM_x86_64=""
+REQUIRES=""
+MAINTAINER="Alexander Verbovetsky"
+EMAIL="alik@ejik.org"
diff --git a/office/BibTool/README b/office/BibTool/README
new file mode 100644
index 0000000000..e52582307f
--- /dev/null
+++ b/office/BibTool/README
@@ -0,0 +1 @@
+Powerful and well documented tool to manipulate BibTeX databases.
diff --git a/office/BibTool/slack-desc b/office/BibTool/slack-desc
new file mode 100644
index 0000000000..7d7c1bf03e
--- /dev/null
+++ b/office/BibTool/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------------------------------------------------------|
+BibTool: BibTool (tool to manipulate BibTeX files)
+BibTool:
+BibTool: Powerful and well documented tool to manipulate BibTeX databases.
+BibTool:
+BibTool:
+BibTool:
+BibTool:
+BibTool: Homepage: https://www.gerd-neugebauer.de/software/TeX/BibTool/en/
+BibTool: Development: https://github.com/ge-ne/bibtool
+BibTool:
+BibTool: