Microsoft's Build 2014 conference is right around the corner. At that event, which kicks off April 2 in San Francisco, Microsoft is believed to be planning to disclose at least some high-level information about Windows 9 .

All we know about Windows 9, at this point, has surfaced thanks to "sources with knowledge about Microsoft's Windows plans, but who asked not to be identified by name." You know... "those people."

But these sources have been pretty solid on Windows information in the recent past. Here's a review of what we've learned from them to date about the follow-on to Windows 8.