[o1o1o1]

Thank you for pointing that out. I am afraid that AoE is probably not one of them though?

Maybe the old AoE versions will be open-sourced one day, that would be awesome.

[pertymcpert]

Probably also because it's a multiplayer game and you want to try to stop cheaters.

[Rohansi]

Steam's DRM doesn't do anything to stop cheaters.