Autotools

Autotools, also known as GNU Autotools, is a collection of build-system tools designed to make software packages portable across Unix-like systems by producing configure scripts and portable Makefiles. The core components are Autoconf, Automake, and Libtool, with auxiliary tools such as aclocal, autoheader, and autoreconf. It enables packages to adapt to different environments by detecting features, libraries, headers, and compilers.

Autoconf generates a configure script from configure.ac (or configure.in) using a library of macros. The script tests the system and creates configuration headers and a Makefile customized for the host. Automake creates Makefile.in templates from Makefile.am files to standardize build targets. Libtool provides a portable interface for building and linking shared libraries.

Typical workflow: writers create configure.ac and Makefile.am, then run aclocal, autoheader (optional), autoconf, and automake to bootstrap. The user executes ./configure to probe the system and produce a Makefile, then runs make and make install.

Strengths include broad portability, mature tooling, and long-standing industry usage. Weaknesses include complexity, verbose generated scripts, and a slower development loop compared with modern alternatives like CMake and Meson. Autotools remains widely used in the GNU project and in many open-source packages, where its emphasis on portability and configurability continues to be valued, despite the learning curve involved in maintaining Autotools-based builds.