so this is a source engine game isn't it?

[pwdcrk]

then i suppose there will be some chances to see it ported on Macs ...
i am just a fool thinking it or there are some REAL chances ?

[iZach]

then i suppose there will be some chances to see it ported on Macs ...
i am just a fool thinking it or there are some REAL chances ?
We don't know if this game will be ported over to Macs. However, there is always a possibility. Especially since this is a Valve game.

[legotrekker]

I'm almost positive this runs on the L4D2 engine, which is currently unsupported on mac computers. However,when Left 4 Dead and Left 4 Dead 2 are ported over, Alien Swarm should follow close behind.

[Cedge]

I'm almost positive this runs on the L4D2 engine,

It's closer to the Portal 2 version of Source, actually.

[bbad89]

Actually, it uses the L4D2 engine, but with some of the improvements seen in Portal 2

[pwdcrk]

ok il will play it on my pc till they will realease it for my "everyday loved" MacbookPro ;)

[shackanaw]

I will let Poodle speak for me:
I don't think that's entirely fair. What they mean is that anything built with the Portal 2 codebase and beyond will have simultaneous releases on the Mac because the framework is built with the Mac in mind and so produces both Mac/PC versions of the game every time they recompile. Games built from a different codebase (GoldSrc; older Source Engine frameworks; SDK) will need to be ported to include Mac support, at which point all future updates for games that use them will be released for both Mac/PC simultaneously.

As disappointed as I am that Alien Swarm won't be available for the Mac at release, I can also see that it's unfair to hold Valve to supporting a simultaneous release for a game that was coded by some of its developers in their free time, using a framework (SDK) that was not planned to have Mac support until much later on (if at all?). Indeed, its entirely possible that the Alien Swarm developers didn't even know that Mac support was a future goal for Valve when they were readying Alien Swarm for release. As it stands, we would actually be asking for Valve to hold back the game from the PC until the (large?) effort of porting the SDK was done for the Mac. Instead, look on the brighter side: the PC folks will be stress-testing the game so that when/if Alien Swarm arrives on the Mac all the annoying gameplay bugs will have been addressed and you'll have a much more fun initial experience with the game!
http://forums.steampowered.com/forums/showthread.php?p=16150845#post16150845

It is running on its own version of Source somewhere between Left 4 Dead 2 and Portal 2:
Alien Swarm branched off of the main tree several months ago. A project will branch off in order to ensure stability so that no external changes outside of the project will impact it. For example, TF2, L4D, L4D2 all live in their own separate branches since they've released to ensure only updates to those specific projects go live and out to the public. It is mainly a quality and stability insurance.
http://forums.steampowered.com/forums/showthread.php?p=16146455#post16146455