What is GNU Libtool?

Introduction to GNU Libtool

GNU libtool is a generic library support script. Libtool hides the complexity of using shared libraries behind a consistent, portable interface.

To use libtool, add the new generic library building commands to your Makefile, Makefile.in, or Makefile.am. See the documentation for details. 

Ref:
https://www.gnu.org/software/libtool/libtool.html