2.6 Microsoft Windows

In 1995, Microsoft released Windows 95, which soon became the most widely-used operating system in the world. Autoconf and Libtool were written to support portability across Unix variants, but they provided a framework to support portability to Windows as well. This made it possible for a program to support both Unix and Windows from a single source code base.

The key requirement of both Autoconf and Libtool was the Unix shell. The GNU bash shell was ported to Windows as part of the Cygwin project, which was originally written by Steve Chamberlain. The Cygwin project implements the basic Unix API in Windows, making it possible to port Unix programs directly.

Once the shell and the Unix make program (also provided by Cygwin) were available, it was possible to make Autoconf and Libtool support Windows directly, using either the Cygwin interface or the Visual C++ tools from Microsoft. This involved handling details like the different file extensions used by the different systems, as well as yet another set of shared library features. This first version of this work was by Ian Lance Taylor in 1998. Automake has also been ported to Windows. It requires Perl to be installed (see section A.1 Prerequisite tools).