Trooper1270: Necrophilia alert!...
Indeed, but no harm done really, and no need to start a similar new thread.
I was quite surprised to see I was the thread starter ... had forgotten this one ... made in the same year I joined GOG.
Stefano_Petrini: Hi I'm a modder, and I desperately need a GOG copy(or any other non-steam copy) of Duke Nukem Forever and its two dlc's to be able to mod dlc multiplayer maps.
I don't think GOG ever had Duke Nukem Forever, just a few of the older Duke games.
As far as yourself goes, I wouldn't hesitate to get a pirated version if you actually own the game, but that is down to you.
That won't help though if you want to share your mod creations with others, unless they are prepared to do the same thing.
Doesn't Steam allow something like you want with their Workshop?
It might be worth communicating with someone at the likes of ModDB about your issue or even Steam themself.