FS2_Open is the original FreeSpace 2 engine, released to the open source community by Volition in 2002. Ever since then, a dedicated team has been hard at work keeping the engine up-to-date, enhancing it, fixing the bugs, and porting it to non-Windows platforms.
Taken from the mission "...but hate the traitor".
SCP 3.6.10
Love this game, still hard to believe this is from a 10+ year old game engine