If you haven't heard already GOG is making their own solution to Steam, with their DRM-free Galaxy client. To add on to it, they are having a vote of whether or not the client will be open source. I have already voted, as have others, and I hope people here take the time to do so. DRM-free content is the future, and so is FOSS.
Link to client: http://www.gog.com/galaxy
Link to vote: http://www.gog.com/wishlist/galaxy/open_source_the_galaxy_client