In this paper we describe COMPAS -- the open-source computing package, dedicated to the computations on synchronizing automata. COMPAS design is based on a generic programming paradigm. This makes the package very powerful because of its flexibility and extensibility. The paper describes shortly the package architecture and its main algorithms and some examples of use. COMPAS allows to easily operate on synchronizing automata, verifying new synchronizing algorithms etc. To the best of our knowledge, this is the first such flexible, extensible and open-source package for synchronization.