Historical Smartphone operating systems

Windows Mobile from Microsoft (2.8% Market Share Sales Q3 2010)^[7][23] (closed source, proprietary)

The Windows CE operating system and Windows Mobile middleware are widely spread in Asia. The two improved variants of this operating system, Windows Mobile 6 Professional (for touch screen devices) and Windows Mobile 6 Standard, were unveiled in February 2007. It has been criticized for having a user interface which is not optimized for touch input by fingers; instead, it is more usable with astylus. However, unlike iPhone OS, it does support both touch screen and physical keyboard configurations.

Windows Mobile's market share has sharply declined in recent years to just 5% in Q2 of 2010.^[24] Microsoft is phasing out the Windows Mobile OS to specialized markets and is instead focusing on it's new platform, Windows Phone.