Any clue how this got a hold of the L4D2 SDK?

[hefty chonker]

Really curious. It's obviously using the L4D2 engine, probably modified too. How?

[[F4G] StoneD0G]

I think the Source (engine) SDK is available for anyone, someone can correct me but there are plenty of non-valve games on Steam using the Source engine.

[Captain Pentium]

Originally posted by StoneD0G:

I think the Source (engine) SDK is available for anyone, someone can correct me but there are plenty of non-valve games on Steam using the Source engine.

Typically you have to own the game in order to use it's SDK.
So having Half Life 2 gives you the Source SDK
Alien Swarm = it's sdk
Left 4 Dead 2 is no exception. Anyone that owns it can access the Authoring Tools of L4D2 and make their own maps/mods.

[Shadowysn]

Except having the L4D2 SDK itself doesn't give you access to the actual source code of L4D2, which is locked behind tight bars from even The Last Stand developers.

Revelations 2012 has far too much things changed, so it's assumed the devs bought a license to the L4D2 source code back when Valve was still handing out licenses for Source Engine games.

I think this is the question 'I don't need a calculator' was trying to ask.

[hefty chonker]

Yeah, I've become an Unreal Engine god since then, so the question has become pretty much obsolete. Thanks for the input nonetheless.