libtool -- The GNU Portable Library Tool
http://www.gnu.org/software/libtool/
GNU Libtool is a set of shell scripts which automatically configure UNIX
and UNIX-like systems to generically build shared libraries. Libtool
provides a consistent, portable interface which simplifies the process
of using shared libraries.
If you are developing programs which will use shared libraries, but
do not use the rest of the GNU Autotools (such as GNU Autoconf and GNU
Automake), you should install the libtool package.
The libtool package also includes all files needed to integrate the
GNU Portable Library Tool (libtool) and the GNU Libtool Dynamic Module
Loader (ltdl) into a package built using the GNU Autotools (including
GNU Autoconf and GNU Automake).
This package includes a modification from the original GNU Libtool to
allow support for multi-architecture systems, such as the AMD64 Opteron
and the Intel 64-bit Xeon.