As of FoX-3.1.2, the library is distributed in several versions. You probably want to get the standard version, which is named simply: FoX-$VERSION.tar.gz This has all unnecessary files stripped out, and is suitable for distributing with your own software. The -full version contains all the necessary files for developing FoX itself, and includes the testsuites. It is considerably larger. The current version (4.1.1) can be found in this directory, older versions are located in subdirectories.