Microsoft's current release is Windows Mobile 6, internally code-named "Crossbow'". It was officially released by Microsoft on February 12, 2007 and Microsoft has promised that it will work seamlessly with Windows Vista.

Windows Mobile 5.0 marked the convergence of the Phone Edition and Professional Edition operating systems into one system that contains both phone and PDA capabilities. A 'Phone' application was included in the OS, and all PIM applications were updated to interface with it. Windows Mobile 5.0 was compatible with Microsoft's Smartphone operating system and was capable of running Smartphone applications.

Pocket PCs running previous versions of the operating system generally stored user-installed applications and data in RAM, which meant that if the battery was depleted the device would lose all of its data. Windows Mobile 5.0 solved this problem by storing all user data in persistent (flash) memory, leaving the RAM to be used only for running applications, as it would be on a desktop computer. As a result, Windows Mobile 5.0 Pocket PCs generally had a greater amount of flash memory, and a smaller amount of RAM, compared to earlier devices.

The first devices to ship with Windows Mobile 5.0 were the HTC Universal (Europe) and the UTStarcom PPC 6700 for Sprint (United States).

The previous release, Windows Mobile 2003 Second Edition added native landscape support as well as other fixes and changes to those features already present in the original release of Microsoft Windows Mobile 2003 for Pocket PC, also known as WM2003. The first device to come with 2003SE was the Dell Axim x30.

Microsoft Windows Mobile 2003 for Pocket PC consisted of the Windows CE.NET 4.2 operating system bundled with scaled-down versions of many popular desktop applications, including Microsoft Outlook, Internet Explorer, Word, Excel, Windows Media Player, and others. Past Pocket PC operating systems include Pocket PC 2002 (launched October 2001) and Pocket PC 2000 (launched April 2000), both running Windows CE 3.0 underneath.