Steam has officially made its inventory system available to all game developers on the digital platform, meaning community sales of virtual items is now possible for all games, not just Valve-sanctioned ones.
The Steam Inventory System - popularized by Valve's games like Team Fortress 2 and Dota 2 - is a "set of new Steamworks APIs and tools that allow a game to enable persistent items that have been purchase or unlocked by individual users without having to run special servers to keep track of these user's inventory."
"This new service adds to the list of APIs available for free to Steamworks developers, including achievements, cloud saves, authentication services, error reporting, leaderboards, matchmaking, Steam Workshop, peer-to-peer networking, in-game overlay, downloadable content, and much more."
Valve hinted in late January that they would enable this for other developers who wanted to let their players get in on the action of buying and selling virtual goods.
It will be interesting to see which developers decide to support this and which games will be able to even come close to the level of virtual goods sales that Team Fortress 2 has managed to generate over the year.
You can learn more about the new Steamworks update here