Valve appears to have stealthily soft-launched the long-awaited Source 2 game engine alongside the overnight release of Workshop Tools for Dota 2, Dota modders are suggesting.

Central to the theory is while Dota 2's assets remain the same in this update, the code is decidedly different — in particular, all files that would share a name with the Source engine are qualified with the number 2, including engine2.dll, vconsole2.exe, vphysics2.dll.

"Everything in this package is a new game," wrote RoyAwesome on the Dota 2 subReddit, a user who has been collecting evidence so far. "It's all the Dota assets and code ported over to Source 2. That's why Hammer is different. That's why the console is different.

"The general consensus around the Source reverse engineering community is that this is really Source 2."

This has since triggered a debate over whether the Workshop is an example of the engine itself, or rather is just related to the tech.

The tools themselves have relatively high system requirements, including a 64-bit version of Windows and DirectX 11 compatible graphics card. In response, Valve has acknowledged "this is a developer focused release and currently has high system requirements." But the company is yet to make a statement regarding the possible Source 2 connection.

Valve confirmed it was working on Source 2, a successor to its long-running Source engine, earlier in 2012. The news was confirmed at the time in a video featuring studio head Gabe Newell.

"We've been working on the engine itself for quite a while." said Newell. At that point, the audio becomes muffled, but according to the transcript provided by the video's author, Newell added, "We've just been waiting for a game to roll it out with." He also said it's a new engine altogether, not a mere extension of the existing Source technology.

We've reached out to Valve for further details and will update when more information is available.