: Pretty sure that this isn't correct. Bungie still owns the file formats and
: the content itself.
Yes they still own it, and they still own the copyright on the Marathon 2 engine code. The thing that's special in both cases is that they have specifically permitted (with different licences obviously) the use of their copyrighted "intellectual properties" (I hate that term) for use in a very unrestricted manner.
The license specifying how we can use the M2 source code is the GPL. I'd be curious to see whatever official letter from Bungie states that we can distribute the file formats and game content and everything else on Trilogy Release. Maybe I'll ask Claude to comment here...