Microsoft and Gas Powered Games have teamed up with Discreet, the creators of 3D Studio Max, the industry standard for 3D modeling and animation, to provide a custom created gmax Game Pack. The free gmax Game Pack will allow for the modification and creation of custom 3D models and animations that can be directly imported into Dungeon Siege.

gmax - http://www.discreet.com/products/gmax/gmax_index.html
gmax download – http://www.discreet.com/products/gmax/gmaxconsumer/