Valve's Steam can now support the ability to deliver add-on content to previously-released games.

The new feature gives publishers the option to sell downloadable content to gamers who want to extend the life of certain titles.

The first game to use the feature is Twisted Pixel Games' The Maw.

Valve explained in a statement, "DLC can now be added to any game on Steam, regardless of whether it was originally purchased via Steam, at retail, or via other digital outlets. It is also a feature of Steamworks, the suite of free tools and services available to game developers and publishers."