Windows CE, or WindCE, is a variation of Microsoft's Windows operating system for minimalistic computers and embedded systems. The secondary usage of CE is in devices in need of graphical user interfaces (point of sale terminals, media centers, web tablets, thin clients) the main selling point for CE being the look and feel of the familiar desktop Windows.

Windows CE is a distinctly different kernel, rather than a trimmed-down version of desktop Windows. It is supported on Intel x86 and compatibles, MIPS, ARM, and Hitachi SuperH processors. Many platforms have been based on the core Windows CE operating system, including Microsoft's AutoPC, Pocket PC 2000, Pocket PC 2002, Mobile 2003, Mobile 2003 SE, Mobile 5.0, Mobile 6.0 Smartphone 2002, Smartphone 2003 and many industrial devices and embedded systems. Windows CE even powered select games for the Sega Dreamcast, was the operating system of the controversial Gizmondo handheld, and can partially run on modified Microsoft Xbox game consoles.

Windows Mobile is an OS platform for mobile devices that is a subset of Windows CE. Currently, Pocket PC (now called Windows Mobile for Pocket PC), SmartPhone, and PocketPC Phone Edition are the three main platforms under the Windows Mobile umbrella. Each platform utilizes different components of Windows CE, as well as supplemental features and applications suited for their respective devices.

Competitors to consumer CE based PDA platforms like Pocket PC are Java, Symbian OS, Palm OS and Linux based packages like Qtopia Embedded Linux environment from Trolltech, Convergent Linux Platform from a La Mobile, and Access Linux Platform from Orange and Access.
In the following table, we listed the main Windows CE release timeline and the timeline for one of its main applications PocketPC/Windows Mobile.

Figure: Windows CE Timeline and Its Dependent Platforms