From FreeSpace Wiki
Prometheus can mean one of the following things:
- GTW Prometheus -- The original Prometheus cannon, from FreeSpace 1. Sometimes called Prometheus O.
- GTW Prometheus R -- A weaker, retrofit version of the Prometheus cannon.
- GTW Prometheus S -- A significantly upgraded cannon over the Prometheus R, supposedly designed to mimic the Prometheus O, though its statistics are noticeably different.