Arkane have released a 2.1 patch as well as releasing the source code of the game. All Arkane patches are culmative, so I had no problem on my retail version of AF. With the source code now available, maybe we will see a couple mods and such.

You can get the patch from here:

http://www.arkane-studios.com/uk/arx_downloads.php

Thanks for the heads up, but you are slightly late.. the 1.21 patch and source were released around january :)

Yea, a bit late. And one of the two known active source code projects is linked in the sticky topic at the top of the forum btw (and here is another but it hasn't released anything yet). There were others but they pretty much died in their infancy. Oh and it's 1.21 patch and it's been incorporated to GOG version since arkane released it :-p.

Just to avoid any confusion for those visiting this thread, let me restate:

The latest patch (which is v1.21, not v2.1) has been incorporated into the GOG version, as Petrell noted. Just download from GOG and install and you've got the latest version.