Symbian is an open platform for smartphones overseen by the Symbian Foundation. It formerly existed as a proprietary mobile operating system under the Symbian OS name, which was under the control of Nokia, Ericsson, Motorola and Psion. Nokia was the majority share holder. In 2008, Nokia acquired complete control of the platform and made it available as an open source platform under the Eclipse Public License (EPL).
Symbian^3 (S^3) platform, the first open source version was released on February 15, 2010, at the Mobile World Congress in Barcelona, Spain. The first devices powered by the platform are expected in the market later this year.
A video introduction of the platform.