It's really a "Frankenstein" of a game in terms of various developers actually, so to at least a small extent, I was expecting some bugs and glitches from the get go. Anyone have the full list of all involved with each component? Would love to see that again.
To the best of my knowledge:
UI:
United Front
Halo: Combat Evolved:
Bungie
Gearbox - (PC port which was used as the base for Anniversary)
343/Sabre (I'm not sure which) - (port of the PC port to 360 and then of that to Xbox One)
Halo: Combat Evolved: Anniversary:
Sabre - New graphics engine
343/Sabre (again, not sure) - port of that engine to Xbox One
Halo 2:
Bungie - Original game
Hired Gun - PC port which I think is the base for this port.
343/Sabre (again, not sure) - porting the PC port to Xbox One
Halo 2: Anniversary:
Sabre - New graphics engine.
Blur - new Cutscenes
Halo 2: Anniversary MP:
Certain Affinity
Halo 3:
Bungie - Original game
Ruffian - port to Xbox One
Halo 4:
343 - Original game
Ruffian - port to Xbox One
Number of games: 5 (I'm including H2A MP as a separate game for development purposes)
Number of engines: 7
Number of companies involved: 9