Libporty is a lightweight portability lib configured by scconfig. It's been tested on various different UNIX and BSD systems, including OSX, and on Linux and Windows. The whole project is written in ANSI C, and does not depend on m4. Only scripting dependencies are (traditional) make and (traditional/POSIX) shell.
If a project is written in ANSI C (C89) and uses any extra feature exclusively from libporty, it will also work on all systems libporty works on. To assist developers in using libporty the Right Way, a lint-like utility called porty is included in the project. Porty can be used to validate C sources for portability.
Documentation is split in the same manner as the project is split:
2021-04-30: new release (1.0.0) features advanced c99tree.