Steam, the PC gaming platform from Valve Software, will be coming to Mac systems in April, while one of the company's most anticipated forthcoming titles, Portal 2, will also be available for Apple machines in the fall.

Update: Later Monday, Valve officially confirmed Steam for Mac would arrive in April.

According to TUAW, the April 2010 edition of GameInformer magazine reveals that Valve intends to start a beta of Steam for Mac in the spring, while a full release of the program has been "targeted for May."

In addition, the article revealed that Windows users who already have a Steam account will be able to re-download games using their existing keys on the Mac. If true, that means PC users could easily migrate to the Mac and play their favorite Valve games — including Half-Life 2, Team Fortress 2 and Left 4 Dead 2 — without having to buy them again for a new platform.

Steam is a cloud-based service that integrates game purchasing and a friend system in one all-encompassing application. By logging in to a Steam account, users can currently download the games they have purchased to any Windows-based computer. But in the future, it would seem, that functionality will be cross-platform, for both Mac and PC.

Last week, Valve began a teaser campaign for the coming release of Steam for Mac. The images released paid homage to Apple's iconic "1984" TV ad, the "Think Different" campaign, the "Get a Mac" campaign and more. Prior to that, users discovered Mac OS X specific files hidden in the latest beta version of Steam for Windows.

In 2007, Valve co-founder Gabe Newell said that there was "no evidence" that Apple had interest in helping developers to bring their games to the Mac. He also noted that he believes the lack of support for games has held Apple back in the consumer space.

But Apple has found great success with games on the iPhone, even making an impact on major players in the portable space like Nintendo. With more than 140,000 applications available for the App Store, a significant number of them are games for the iPhone and iPod touch.