Valve made a brief announcement on Friday that they will be allowing the download of user-created game mods
directly from Steam. "Once installed, these MODs will appear in your 'My Games' list and will receive automatic updates just like other games on Steam. Also, these MODs now take advantage of Steamworks, which provides stat tracking and tighter integration with the Steam community." Mods will be available for five different games to start, and more in the future.