GOG.com have announced "Galaxy" a completely optional game client that works a lot like Steam. Not only is it entirely optional but it allows you to be fully offline anytime. They also stated elsewhere it's being built with Linux in mind.
While Linux wasn't mentioned in their video earlier today it will be supported later on when they support Linux on their store later this year. It will support "cross-play" which is online gaming with Steam titles that support it as well. Their Steamworks-like system for things like achievements can be turned off it seems to, it's all optional.
QuoteWe're not forgetting Linux guys. We'll be giving more info later this year.
Galaxy is being done with PC, Mac and Linux in mind.
Really fantastic news to see GOG.com fight to keep things simple for users. Since if you don't want the client you don't have to have it.
Quite exciting to see how well the client works, as Desura still haven't decided what they are doing with their client on Linux since Linden Lab took over.
See the full article and video from gog here.