Today marks a slight change in how Valve (creators of hit game franchises like Half-Life, Left 4 Dead, and Portal) utilizes its incredibly powerful Steam service. As promised, Steam will now carry a selection of non-game software titles, available for download. While that's all fine and dandy -- where's the Mac compatibility?

When Valve first mentioned its planned introduction of non-game software titles, Mac programs were also part of the deal. Unfortunately, of the six programs made available for sale today, none of them are compatible with Mac OS. Kind of a letdown.

Granted, there's still a very good chance Mac software will find its way into the store in the future. The initial selection of titles is pretty light, and if the store is successful, no doubt Valve will continue to add new software titles.

But just in case you're capable of using Windows programs through a virtual machine, Boot Camp, or otherwise, the programs are actually pretty interesting. The software focuses primarily on game development art or testing, like 3D modeling program, 3D Coat, or benchmarking tool, 3DMark 11. There's also art and photo editors, like CameraBag 2 and ArtRage Studio Pro.

The prices on software vary heavily, from free (Source Filmmaker) to $89.10 (3D Coat). The entire library of titles is on sale for 10-percent off this week. There's no word yet on how often Valve will add new titles to the marketplace.

A large part of the draw to Steam's non-games marketplace is integration into the overall Steam ecosystem. Certain titles will link up with the Steam Workshop system, allowing anyone to make in-game items or mods, for example. The software can also tap into's Steam's cloud, as well as the convenience of re-downloading titles to other computers based on one Steam sign-in.

We'll let you know if Valve announces Mac-ready software in the future.

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