Do I need two licenses to my two operating systems (Win and Mac)?

[robertoog]

YC was I correct in what I said? because I am not sure...

Concerning San Andreas or Amnesia or in general?

Neither of us know of how the user obtained a copy of Amnesia. Many online distributers (e.g. Steam, Desura) of Amnesia allow downloading Amnesia for multiple operating systems, including the Frictional Games store. I only know of the PC version for Amnesia on DVD.

I was just using San Andreas as an example (on a slightly unrelated note: I am pretty sure that all GTA games before IV have a mac version) but I was actually referring to Amnesia. Like you said though online services (steam/Desura/etc.) allow you to install it on either mac or PC if its available. If the user bought it retail than I don't know but if he bought it on Steam he should be able to install on any computer.

I may be wrong about this but don't most games today that are for both mac and PC have the installer on the same disc? or am I mistaken? I think I am correct though.

I've not bought any license yet, I would like to buy one that allows me to play the Amnesia game in my Windows PC and my Mac, also would be great if I could play on my Ubuntu Linux too, where should I buy the Amnesia game to play in all my operating systems? (I don't want the DVD version).