ktchong: A while ago, there was a discussion in here about games that were purchased on GOG but could be redeemed on Steam, i.e., people who bought the games here on GOG could ask the developers for Steam keys for those games. The discussion made a list of those games. I can't find the thread. Can anyone point me to it?
ArmA 1, 2 and Cold War spring to mind. The Steam keys for a given game are listed in your library shelf when you expand to see the full information, or they were anyway. Generally speaking, this has been done only with very few games and mainly they were games that used Gamespy which went out of business, and eventually the games were updated to use Steamworks for multiplayer, so that's how they allowed GOG users to still retain multiplayer functionality - by offering up Steam keys.