It's easy to forget -- as Microsoft wants you to -- that the Windows Mobile operating system is built on top of an embedded Windows CE core.
Windows Mobile 6.5 seemingly is built on a customized version of Windows Embedded CE 5.X. Windows Mobile 7 is likely to be built on the Embedded CE 6.X platform, I'd wager. (I'm hedging because don't know either of these things for a fact, as Microsoft hasn't answered my questions about this.)
But there's yet another new version of Windows Embedded Compact (the new name for Windows Embedded CE) in the works that is codenamed "Chelan." Microsoft officials provided a sneak peek of Chelan in a TechEd 2009 pre-conference session this week.
Chelan, known officially unofficially as Windows Embedded CE 7.0 is the successor to Microsoft's Windows Embedded CE 6.0. Chelan is on track to be released to manufacturing in 2010 (just like "Quebec," which is the next version of Windows Embedded Standard, a k a XP Embedded).
Microsoft officials refused to say anything more about Chelan. The information company officials shared at the TechEd preconference seems to be considered to be under non-disclosure.
(Microsoft has shared a bit more about Quebec, however. It is an embedded, componentized version of much of the functionality in Windows Vista. 7, according to Microsoft.)
The Windows Mobile team is just one of the entities which build on top of the Embedded CE platform; Microsoft also licenses the Embedded CE components to other Microsoft teams, as well as third-party vendors. As Senior Technical Product Manager Mike Hall explained in a blog post a couple of years back:
"Windows CE gets released to two sets of customers, the general embedded developer (who builds cow milking machines, sewing machines, industrial robots, set top boxes, and a range of other cool devices) and "Microsoft internal" customers (Windows Automotive, Windows Mobile, others).
"The Windows Mobile team choose their own specific set of Lego blocks (operating system components), add their custom shell, applications (like Office Mobile), and device specific technologies (like the connection manager for example) - the result is a uniform set of operating system technologies, applications, shell and APIs that are consistent across all Windows Mobile devices - this means that an application written for one Windows Mobile smartphone (or Pocket PC) should run across all Windows Mobile devices....Windows Mobile OEMs don't have the ability to customize the underlying operating system/technologies because that would modify the exposed APIs on the platform, but do have the ability to add their own specific applications/services to the Windows Mobile device image (today screen plug-ins, applications like VoIP, games, or others)."
Given the lag time between a new Embedded CE release and the corresponding Windows Mobile release (example: Windows Mobile 6 was built on top of Windows CE 5.2), I'm highly doubtful Chelan is what's going to be inside Windows Mobile 7 -- in spite of Microsoft's claims that Chelan will help "to deliver really immersive user experiences quicker and easier than previously possible."
Instead, I'm betting Chelan will power Windows Mobile devices in the post-Windows-Mobile-7 timeframe. And I'm betting we'll see Chelan inside more portable devices than just Windows Mobile phones....