Deus Ex: Human Revolution game director Jean-Francois Dugas in an interview with Shacknews.
When asked if the PC version of the game was done in-house, Dugas said: “No," then added "Well, it was done in-house, but with a partnership.” In other words, the game has been outsourced to another developer, in this case, , a Dutch developer best known for developing games in the Legacy of Kain series, the latter games in the Tomb Raider series including Guardian of the Light, and Kane & Lynch 2: Dog Days.
Dugas then reassured: “All the design and changes to the design has been done in Montreal and sent to (Nixxes). We review the builds. We review and then give comments about what works and what doesn’t. It’s the same process. It’s the exact same process, except that the programmers aren’t in the same office. “It’s the same game and the same creative team taking care of it."
“It’s the same game and the same creative team taking care of it."
In other words, Eidos Montreal is doing the designing and Nixxes is doing the heavy lifting, with Montreal looking over their shoulders.
The reason for this is simple, according to Dugas: there isn't enough manpower in Montreal alone to handle the multiplatform work, spread between the Xbox 360, PlayStation 3 and PC: “It was more of a logistic problem more than anything else and having enough people to make sure it’s all on the same level, all the time. So, yeah. It was more about manpower and logistics.”
Dugas does state that the PC version of the game is the version that he prefers to play.