I've been seeing this misconception around the forums that you need to log in to Steam to run the Steam version of KSP, and I haven't really seen this mentioned much but in passing a couple times, so I thought I'd clear the air on this. Steam DOES allow DRM-free games, and KSP is one of them. If you have the Steam version, you can run it without going through Steam, or even being logged into Steam. Just run the KSP.exe. You can even copy the whole folder in your Steam directory, paste it somewhere, and treat it just like the regular ZIP version. I didn't realize this until AFTER I paid the extra $23 for the zip version, but I'm not too upset since I've gotten/will get far more than $46 worth out of it. Hopefully this helps some of you out