slibtool is an independent reimplementation of the widely used libtool,
written in C. slibtool is designed to be a clean, fast, easy-to-use.
slibtool maintains compatibility with libtool in nearly every aspect of
the tool's functionality as well as semantics, leaving out (or turning
into a no-op) only a small number of features that are no longer needed
on modern systems.

This does not conflict with GNU libtool included with Slackware.

To use slibtool instead of libtool export this to your environment.
  export MAKEFLAGS='LIBTOOL=slibtool'

Alternatively only shared or static libraries can be built.
  export MAKEFLAGS='LIBTOOL=slibtool-shared'
or
  export MAKEFLAGS='LIBTOOL=slibtool-static'