Originally Posted by Hendrik
Wndows Mobile= Windows CE
Windows CE is the overall name for all handheld OS versions by Microsoft. Windows Mobile 6 will be the next OS.
AFAIK CE5 != Mobile 5 (while Mobile 5 is based on CE 5).
At the same time CE4 != Mobile 2003 (while Mobile 2003 is based on CE4, and Mobile 2003SE is based on CE4.x)
Therefore, CE6 != Mobile 6 (Photon, formerly known as Crossbow), but Mobile 6 will be based on CE6.
This isn't like XP Home vs XP Pro, mind you. The Mobile OS's are stripped down versions of CE, for "better usability". Changes in start menu, lack of task manager are two noticable differences. IIRC programming for Mobile is slightly different from programming for CE. Compatibility for apps is not garunteed between both versions of the same OS - tho some apps do run on both.
Zircon Axia ran on CE rather than WM. It had compatibility problems with WM apps, and in fact, you were advised to give up immediately if a given WM program didn't install correctly.