An open source smartphone operating system for ARM processors from Nokia. In 2010, more than a third of all smartphones sold worldwide were Symbian phones (for details, see smartphone operating system). In 2011, Nokia announced that, going forward, it would use Microsoft's Windows Phone operating system for its smartphones. Symbian uses the WebKit browser, and apps are written in C++, Qt, Flash and Java (J2ME). Prior to the Symbian platform, which combined OS and all related components into one system, versions used numbers such as Symbian OS 9.1, 9.2 and so on. Platform releases changed their designations to Symbian^1, Symbian^2 and Symbian^3. From EPOC to Symbian OS/S60 to Symbian The Symbian platform started out in the late 1980s as the EPOC operating system for PDAs from the Psion Software division of London-based Psion PLC (www.psion.com). In 1998, Nokia, Ericsson, Motorola and Psion created Symbian Ltd. to support the EPOC OS as an independent entity, and EPOC OS was renamed Symbian OS. In 2009, the Symbian Foundation was launched to offer the Symbian platform under an open source license, which includes the Symbian OS, the S60 user interface and related components. In late 2010, Nokia took over Symbian development, and the Foundation closed its operations except to provide licensing and legal support. See smartphone.