Windows CE is based on the Microsoft Windows operating system but is designed for including or embedding in mobile and other space-constrained devices. Although Microsoft does not explain the "CE," it is reported to have originally stood for "Consumer Electronics." Windows CE is used in several brands of handheld computers and as part of cable TV set-top boxes built for TCI. It competes with EPOC and also with similar operating systems from 3Com (for its PalmPilot) and other companies. Microsoft argues that Windows desktop system users will find that products with Windows CE provide a familiar user interface.