Download the sources here: http://arkane-studios.com/uk/arx_downloads.php
They also released a patch to fix some problems and can be downloaded at the same place.
I haven't played the game myself but you can buy it on GOG and steam it seems.
I remember this game. It came bundled with a sound card I bought in 2004. The game itself is from 2002.
I played it for a while back then but I got bored after 40 minutes or so. If you like RPGs that only take place in a single, big dungeon though, you might like it. The graphics are total crap though by today's standards.
This is great news. Arx Fatalis is a pretty cool first person RPG that got lost in the shuffle a bit since Morrowind came out about the same time. It takes a bit of getting used to the control scheme and the magic system, while interesting, also takes some getting used to. The game world is kinda cool as long as you don't mind never seeing the sky. The planet's surface is frozen since the sun died out and now everyone lives underground. There are a bunch of different races and each essentially lives on their own level underground. There are cities and castles and all that usual fantasy stuff but it's all underground.
The game runs fine under wine with some minor annoyances but it would be great to have a native client. Also this opens up the way for possible graphical enhancements. The game looked fairly good back when it came out, but by today's standards it definitely looks a bit dated.