The latest update for Dota 2 appears to be running the Source 2 engine.
Valve's Source engine powers games like Half-Life 2, Team Fortress 2, Counter-Strike: Source and Portal. Rumors of a new release, Source 2, began in January this year when a NeoGAF user posted a leaked powerpoint presentation that showed images from Left 4 Dead 2 reportedly running in the new engine. Now, code sleuths on Reddit report that Valve has soft launched the engine in the latest update to Dota 2. The latest update includes content for the Dota 2 Workshop DLC, a modding toolset that can be used to create maps for the game. Reddit user RoyAwesome reports that the workshop is running on the Source 2 engine, with changes to file names, script changes, and a new command console as proof.
"Everything that would share a name with Source is named '...2'. That's 'engine2.dll', 'vconsole2.exe', 'vphysics2.dll'," says RoyAwesome. "[The new script] also allows for different dlls to load and render different assets (vmaps are rendered by worldrenderer.dll, etc). This is quite a bit different from Source 1, as they had a large number of things in the engine libraries. This bit alone would indicate a significant amount of engine work has been done to split these bits out of the engine and into their own libraries." If the Workshop really is running Source 2, Dota 2 is a great place to test out the engine, with over 7 million players in April.
Valve has not confirmed that the update is running Source 2, but has certainly be keeping busy this year. The Steam controller got a major redesign last month, adding an analog thumbstick instead of a d-pad. Valve is also working to make the Steam controller compatible with Dota 2, despite the challenge of converting a keyboard-heavy game. With $5 million on the line at the latest international Dota 2 competition, I'm not sure the pros will be picking up a Steam controller, but I can see the appeal of playing a few matches from my couch.