Windows Mobile was Microsoft’s family of operating systems for handheld and pocket-sized devices in the decade before the modern touchscreen smartphone. It was built on Windows CE, a compact, modular operating system that Microsoft created independently of desktop Windows but gave a familiar Win32 programming surface. On top of Windows CE, Microsoft layered consumer platforms: first the Palm-size and Handheld PC products, then the Pocket PC introduced in 2000, and from 2003 onward the unified Windows Mobile brand, which included both touchscreen Pocket PC devices and keypad-driven Smartphone editions.
The platform deliberately echoed the desktop. Pocket PC devices ran pocket versions of Microsoft applications, including Pocket Word, Pocket Excel, Pocket Outlook, and Pocket Internet Explorer, and synchronized with a desktop PC through ActiveSync. The user interface borrowed the Start menu and window metaphors of Windows, and stylus input with on-screen text entry mirrored the desktop experience in miniature. For Microsoft, the strategy was to make the handheld feel like an extension of the Windows PC that businesses already ran.
For developers, Microsoft provided the eMbedded Visual Tools suite, documented in its own MSDN materials. As described in Microsoft’s January 2001 MSDN Magazine, eMbedded Visual Tools 3.0 bundled eMbedded Visual C++ and eMbedded Visual Basic with device emulators and SDKs so programmers could build native Windows CE applications against the Win32 API. The toolchain was later refreshed as eMbedded Visual C++ 4.0 for Windows CE .NET. Microsoft subsequently added the .NET Compact Framework, a trimmed-down version of the .NET runtime that let developers write managed Pocket PC and Smartphone applications in C# or Visual Basic .NET, broadening the pool of programmers who could target the platform.
Windows Mobile competed directly with Palm OS, Symbian, and BlackBerry through the 2000s, and it found particular traction in enterprise mobility, ruggedized industrial handhelds, and barcode-scanning devices, where its Windows lineage and Exchange email integration were valued. It also powered a generation of touchscreen and keyboard smartphones from manufacturers such as HTC.
The launch of the iPhone in 2007 and Android afterward exposed how dated the stylus-driven, desktop-derived interface had become. Microsoft eventually abandoned the Windows Mobile codebase entirely and started over with the touch-first Windows Phone, which was not backward compatible. Windows Mobile and the Windows CE foundation beneath it nonetheless represented Microsoft’s substantial and long-running attempt to extend its Windows franchise into the pocket, and they defined the Microsoft handheld experience for nearly a decade.