  Gravitational-wave observations have just started probing the properties of
black hole binary merger populations. The observation of binaries with very
massive black holes and significantly asymmetric masses motivates the study of
dense star clusters as astrophysical environments which can produce such events
dynamically. In this paper we present Rapster (for "Rapid cluster evolution"),
a new code designed to rapidly model binary black hole population synthesis and
the evolution of massive star clusters based on simple, yet realistic
prescriptions. We also perform a thorough comparison with the Cluster Monte
Carlo code and find generally good agreement. The code can be used to generate
large populations of dynamically formed binary black holes.
