OPUS (Observatoire de Paris UWS System) is a job control system developed using the micro-framework bottle.py . The Universal Worker System pattern v1.1 (UWS) as defined by the International Virtual Observatory Alliance (IVOA) is implemented as a REST service to control job execution on a work cluster. OPUS also follows the recent IVOA Provenance Data Model recommendation to capture and expose the provenance information of jobs and results. By following well defined standards, the tool is interoperable and jobs can be run either through a web interface, or a script, and can be integrated to existing web platforms. Current instances are used in production by several projects at the Observatoire de Paris (CTA/H.E.S.S, MASER, ComPOSE).