Having checked the hashes of both current (1.8.1.2964) Windows releases of KSP found on Steam and GOG, they are both the same (SHA1: 699FC07D2826A5B10BECD978401C7530D6E291AB), with this I feel it is appropriate to class the Steam release as completely DRM-free with the only limitation being its download via the Steam client.
Talk:Kerbal Space Program
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