A rather large group of people who denote themselves as "Role Players" who, as the name implies, play roles in a specific context in a specific universe. These universes include the Half-Life 2 Universe, based on the game Half-Life 2, and the World War 3 Universe, one that is merely our current universe in the not too distant future, covered by war and destruction.
However, outside of that "Role Playing" there are the nebulous forums. A collection of boards and threads, most of them memes, that within them contain...well memes. Away from the memes there are some rather more serious oriented boards. There are also a few notable members, as noted below:
@RetroPirate1 - A Swedish Confederate. Thats all you need to know.
@Blackquill - Both the HL2RP Server Director and a Head Staff member of the community. He does a lot.
@alex - Founder (As far as my knowledge dictates) of nebulous
@MaXenzie - Sexually-Attracted-To-Robots-Slash-Steam-Powered-Giraffe-Media-Developer-Man
@Chris .P. Bacon - Bacon
@Subeh - Aussie "Abusive" Staff