 Windows Mobile 5 @.@ 0 , originally codenamed " Magneto " , was released at Microsoft 's Mobile and Embedded Developers Conference 2005 in Las Vegas , May 9 – 12 , 2005 . Microsoft offered mainstream support for Windows Mobile 5 through October 12 , 2010 , and extended support through October 13 , 2015 . It was first offered on the Dell Axim x51 . It used the .NET Compact Framework 1 @.@ 0 SP3 , an environment for programs based on .NET. Windows Mobile 5 @.@ 0 included Microsoft Exchange Server " push " functionality improvements that worked with Exchange 2003 SP2 . The " push " functionality also required vendor / device support With AKU2 software upgrades all WM 5 @.@ 0 devices supported DirectPush . 
