Since looking glass studios kicked the bucket, the games rights have been in limbo. Go to this site and scroll down till you see "Where to get it:" Then enter the number you see in the graphic and thats it.
(dont download more than 1 thing at once or use a dl manager on this site, you will be banned )
Also be sure to sure to get this updated graphic pack
http://perso.wanadoo.fr/etienne.aub...irth_Beta_1.zip (direct link)