The Codex is another work of machinima. Like Red vs Blue, it's based on Halo (Halo 2, in this case). It's more like the source material, in being a non-comic work, generically interested in sf, and with lots of fighting.
Paired with ILoveBees, the Halo series has become quite the linchpin for digital media production. For example:
That's from the fan art section of the main Codex site: fan art based on fan fiction (based on a sequel).
(via Long Tail)