I'm on linux, and at first i downloaded the installer and it didn't work..... i thought i could just get wine(windows emulator) after i installed that.
So i got wine and then downloaded the installer again, after that installed the game pretty quickly and had no issues getting the game to install.
However it will not start up the game. > : | It loads most of the checks and then says it failed. I got Arma II :free so it's not like i paid for something that doesn't work.
I'll get it to work eventually though, other linux users seem to be able to run it as there are linux servers available to play on.