Dungeon Siege offers a Siege Editor in order for gamers to create their own quests called Siegelets. DS also makes it possible for gamers to trade online and offline characters.

Game Ogre's Dungeon Siege Review
Does this Diablo-wannabe succeed in surpassing the hack and slash master?

Dungeon Siege Cheats
Tear up more monsters in this hack and slasher that fell short of achieving the same support as the Diablo series.  

Dungeon Siege
Official site by Microsoft where you can find the tool kit for making mods and maps.

Copperhead: Retaliation 
Total conversion of Dungeon Siege with a sci-fi theme.  

Dungeon Siege Character Trading  
Learn how to trade your Dungeon Siege chararacters online. You can also download a few characters.

Dungeon Siege Heaven   offers such DS goodies as FAQs, cheats, the Secret Chicken Level info, and multiplayer game info. Dungeon Siege Developer's Guild   Share codes with other devlopers in order to make Siegelets. Dungeon Siege Center   Despite a note from one of the site managers saying that the site will not be updated much in the future, it still offers patches, modifications, interviews, and forums.