Valve's announcement that their Steam service would soon be available to Mac users is huge news to the Mac gaming community. While the iPhone and iPod touch have taken off as gaming platform, the Mac has languished in a sort of gaming limbo. Sure we get games, but they're usually a few months--or even years--behind the Windows version and some games are announced and never materialize. With today's announcement, The Mac has taken another step to becoming a real gaming gaming platform.

We had a chance to talk Steam's Project Manager, John Cook about their move to the Mac platform, the future of Steam and Valve on the Mac, third-party developers and native- versus Cider-ported games on the Mac. 

What convinced Valve to create a Mac version of Steam?

John Cook: We recently announced Portal 2 in cooperation with the Steam community, and that's an example of the transition we're going through between entertainment as a product and entertainment as a service.  Another example of entertainment as service would be the 100+ updates to Team Fortress 2 that we've released since it launched in 2007.  As a result of that on-going service of Team Fortress 2, our highest sales for the product actually occurred 18 months after we launched.  In general, service businesses need to be as close to and as connected to their customers as possible.

In order to support entertainment as a service, you need open, high performance Internet clients, and the Mac does a great job at that.

What were some of the technological hurdles you encountered while porting Steam?

JC: Due to the fact that Mac OS X implements the POSIX subsystem, the difficulty of porting Steam was fairly well understood in advance.  That said, the two biggest work items were moving Steam's download engine and the UI rendering engine to Mac OS X. The Steam download engine relied upon some Windows-specific features, notably IO Completion Ports. Additionally, Valve's products use an internally developed windowing toolkit called VGUI, as does Steam. As a result, VGUI had to be adapted to the Mac OS X windowing system.  In general, we benefitted from the fact that we already had Linux binaries for many core Steam components, due to our support for Linux builds of Dedicated Servers for our multiplayer games. Beyond the functionality of the Steam client software, back-end Steam systems have been designed to collect crash dumps and hardware surveys from Mac OS X users just like Windows users.

How are you porting the Valve games to OS X? Are you using Cider?

JC: We look at our move to Mac OS as a long-term investment, so it really makes the most sense to do native versions of our games for Mac OS X rather than rely on a virtualization solution. We've been working closely with Apple to help them refine their OpenGL implementation so it works well with games. While we'll be rolling out the Valve back catalog this spring, we have integrated Mac OS X into our development process and will be releasing new titles such as Portal 2 day-and-date on Mac OS X going forward. Simply put, the Mac has been integrated into our core development process at Valve, with Mac OS X versions of our games compiling from the same source code as our Windows and Xbox 360 versions. Every time a developer checks in code, it gets built and tested on Mac OS X, right alongside Windows and Xbox 360.

You're currently beta testing a new Steam UI, will the Mac beta be based upon that new UI?

JC: Yes.

In the future, will OS X versions of Valve games be released the same day as Windows versions?

JC: We will release our games on the Mac the same day we release on Windows. In addition, Steam now implements a new feature called Steam Play. With Steam Play gamers will automatically get the right version on whichever machine they are playing on. If you play Left 4 Dead 2 on your home PC, you can continue playing on your Mac notebook while you are traveling. We expect most third parties to take advantage of Steam Play as well.

Updates are also a big issue - we will release updates for the Mac simultaneously with updates for PCs.

What your thoughts on how this will affect Mac gaming?

JC: We consider this to be the most important Steam development since the service was first announced. Releasing Steam on Mac OS X will also make the Mac gaming market much less of a mystery to the industry in general. Due to the real-time sales reporting capabilities of Steamworks, our partners will be able to better understand how their products are performing across Steam-supported hardware platforms. Additionally, the industry will gain a better understanding of the hardware mix that their customers are using, since we will be integrating Mac OS X data into our ongoing hardware survey http://store.steampowered.com/hwsurvey/ .

Which third-party developers are currently working with Valve to get their games ready for the Mac?

JC: Initially, as we did with the first set of third party titles delivered via Steam, we'd like to harvest all the great titles already available for the Mac and deliver them to Mac OS X users via Steam. In the future, our goal is to build the Mac Steam channel to a point where every publisher and developer automatically adds a Mac OS X version to the list of platforms in development for all their multiplatform games.

When can we expect the Beta to go live?

JC: We will release Steam and our games in April.

Will the beta be open to anyone or is it invite only?

JC: It will be open.

How can our readers sign up to get a slot in the beta?

JC: We will be issuing a follow up release when the beta has opened.

Are any of the developers/staff hard-core Mac users?

JC: Big time. Gabe Newell, our president, worked on a 6Mhz Lisa running a Mac emulator in his first post-college job. Some of us still have our Apple II computers from college in our house. And it seems like every day there are more people vying to get on the "Mac project."

Will Mac users be able to set up dedicated Steam servers like Windows users?

JC: Yes

For years the Mac gaming community has been promised that soon we'd have "insert hot game of day" on the Mac, and many times, those titles never materialized. Maybe we're just being cautious, but this is totally going to happen right?

JC: Totally.

Just checking.

Are there plans for an iPhone OS version of Steam for the iPhone or iPad?

JC: Right now we are only working on the Mac OS X.