Bioinformaticians are tackling increasingly computation-intensive tasks. In the meantime, workstations are shifting towards multi-core architectures and even massively multi-core may be the norm soon. Bag-of-Tasks (BoT) applications are commonly encountered in bioinformatics. They consist of a large number of independent computation-intensive tasks. This note introduces PAR, a scalable, dynamic, parallel and distributed execution engine for Bag-of-Tasks. PAR is aimed at multi-core architectures and small clusters. Accelerations obtained thanks to PAR on two different applications are shown.