This isn't an issue, right?

Just checking it works like in Steam. Same account - I can play on both computers, one at the time of course?

You can play on as many computers as you have in your household.


From the FAQ - https://www.gog.com/support/website_help/downloads_and_games

9. Can I enjoy my purchases both on my laptop and desktop computer at home?
Yes. We do not limit the number of installations or reinstallations, as long as you install your purchased games on computers in your household. So yeah, if you've got a render-farm in the basement, you might actually break the world record for the number of legal Witcher installations in one household. However, if you think about installing your game on a friend's machine or sharing it with others then please don't do it, okay?The same principle applies to movies - you're free to watch them anywhere you want, with anyone you want, as long as you don't share them with people who haven't purchased them.

Yes, you get access (when available) to the Windows, Mac, and Linux builds. You can download whichever one(s) you want.

Thank you. Don't worry, I just don't trust windows with my payment options.

Me too.
I just do purchases in the Mac.

Indeed, this is not an issue. You could even do purchases from a computer that is not in your household (f.i. at work ) , if what you do is just purchasing. The only restriction is that you should only install on computers that are part of your household , and even then you could perfectly install a game on both your mac and your pc.

Didn't that bit used to say UT2004 installations?

I recall it saying Fallout, but then again, The Witcher wasn't released on GOG back then.

It still said "Fallout installations" up until summer 2014, when I signed up -- half a year after the Fallout titles went on their long holiday; going by the Wayback Machine's snapshots of that page, they must've changed it to "Witcher installations" some time between July 28 and August 23. (Had I not checked the Internet Archive, I would've sworn that it said "Fallout" up until some time last year.)

EDIT: Also Fallout had been gone; it has been back for a good while now. ;)

Technically, the game that was called "Fallout" (and is now called "Fallout Classic") is still gone; on the other hand, there's a newer game called "Fallout" that was added more recently. (Of course, the games are the same game when you actually install and play them, but they're technically different games in gog's database.) Actually, unlike Steam, GOG has no way to check how many computers you're playing the game on at any time. That's part of the point of being DRM-free.

It still has been gone ;-)

It is a failure of English grammar.