Early last year, some developers were worried Microsoft planned to retire its DirectX -- the gaming/graphics programming interfaces that the company has baked into Windows for years. Given the company had only delivered minor point releases to DirectX since 2009 and was backing away from XNA support with Windows 8 and Windows Phone 8 , many feared the worst.

But on March 20, 2014, Microsoft officially took the wraps off DirectX 12 at the Game Developers Conference.

DirectX 12 will be supported across phones, tablets/PCs and Xbox One. The Direct3D 12 piece, which is what Microsoft disclosed today, will be supported in "Holiday 2015 games," meaning games delivered in the Q4 2015 timeframe.

Microsoft is advising users that if they have PCs with "supported graphics hardware," which they claim encompasses more than 80 percent of "gamer PCs" currently sold, they will be able to run thesee games. DirectX 12 also includes graphics tools for developers and other technologies which Microsoft is going to make available "at a later date" once DirectX 12 3D is made available.

A new Microsoft blog post notes DirectX 12 supports, as had been rumored, a lower-level of hardware abstraction than DirectX had previously, which will allow games and other graphic-intensive applications to better utilize CPU and multithreaded scaling. Significant performance and rendering improvements are the result, officials said.

Microsoft officials said during a press conference that the company is aware of requests for Windows 7 support with DirectX 12 but didn't commit to delivering it. Given the "holiday 2015" timing discussed today, I'm assuming the Windows 9 (a k "Threshold") and Windows Phone 9 operating systems will include the DirectX 12 application-programming interfaces.

For a blow-by-blow account of what Microsoft and its hardware partners said at GDC today, PC Perspective did a live blog of the announcement. Microsoft did not allow live streaming of the DirectX 12 unveil.