polymake is open source software for research in polyhedral geometry. It deals with polytopes, polyhedra, and fans as well as simplicial complexes, matroids, graphs, tropical hypersurfaces, and other objects. Supported platforms include various flavors of Linux, FreeBSD, and Mac OS.

The documentation is available at polymake.org.

polymake is available via package manager for various linux distributions. You can also install polymake from source. The installation instructions for Mac can be found here.

You can download the source code here. Alternatively you can find a read-only mirror (squashed) of the source code on github.