COMPASS (COMPletely Arbitrary Sequence Simulator) is a python program designed to simulate sequence evolution along any arbitrary state space, allowing it to simulate not only DNA and amino acid sequences, but anything you can conceive of. Code for the command-line version COMPASS is found within the compass folder, with the main script in the bin/ folder. and examples of both matrices and trees required to run compass are found within the examples folder. Several common matrices are found within the matrices folder, and more can be created at will. For full details on how to run COMPASS and the options available with it, please consult the user manual provided in this folder.