Windows CE

A variation of Windows for minimalistic computers and embedded systems. Windows CE is a distinctly different kernel, rather than a 'trimmed down' version of desktop Windows. It is supported on Intel x86 and lookalikes, MIPS (see MIPS architecture), ARM family and Hitachi SH processors.

Windows CE is optimized for devices that have minimal storage - a Windows CE kernel may run in under a megabyte of memory. Devices are often configured without disk storage, and may be configured as a 'closed' system that does not allow for end user extension (for instance, burned into ROM). Windows CE conforms to the definition of a real-time operating system, with a deterministic interrupt latency. It supports 256 priority levels and provides for priority inversion. Unlike UNIX-like operating systems, the fundamental unit of execution is the thread, providing for simpler, faster concurrent programming (see Thread (computer programming)).

The Pocket PC is a personal digital assistant based on Windows CE. There are also cellphones, appliances, industrial controllers and other electronic devices based on Windows CE.