Microsoft is trying again with the mobile OS market. Recently, it announced yet another mobile OS product. The company has already the Windows Embedded Compact product in the market and the Windows Mobile 6.5 OS product. Oh, ya, there is also the Kin, which runs a customized version of the Windows Phone software. The latest attempt will be titled Windows Phone 7 and will be based on the Windows Mobile and the Windows CE core.
The Windows Phone 7 won't be able to run programs from either of the previous versions of Windows mobile OS.
It gets a little more complicated. There will be two versions of the OS launching in the next year or two. Each version contains a different core OS.