The Witcher 2, Frozen Synapse, and Starbound are among the latest games that GOG will let you redeem free on their DRM-free store if you own 'em on Steam. The virtuous virtual vendors of vintage (and virgin) video games call this process GOG Connect. The offer comes and goes -- though the games are for keepsies -- and the lineup shifts, so do have a gander if you fancy some handy DRM-free backups.
Head on over to the GOG Connect page, sign in to a GOG account, then connect it to your Steam account, and it'll have a look to see what you can get. It'll permanently add the games to your GOG account and, obviously, you'll still keep them on Steam.
It's not huge but it's handy, isn't it? I'm sure GOG are hoping I'll stick around and come to them first next time I'm shopping but hey, I'm fine with that.
This latest GOG Connect offer will mostly end on November 13th at 10:59am - the same time as GOG's autumn sale will end. The Witcher games will be available a little longer, until December 7th.
Here's the full latest GOG Connect lineup:
Broken Sword: Director's Cut
Broken Sword 2: Remastered
Metro 2033 Redux
Motor Racer 2
Moto Racer 3 Gold
Risk of Rain
Sins of a Solar Empire: Rebellion Ultimate Edition
The Witcher 2
The Witcher Adventure Game
Worms World Party Remastered