Symbian was a mobile operating system (OS) and computing platform designed for smartphones and currently maintained by Accenture. Symbian was originally developed by Symbian Ltd., as a descendant of Psion's EPOC and runs exclusively on ARM processors, although an unreleased x86 port existed. The current form of Symbian is an open-source platform developed by Symbian Foundation in 2009, as the successor of the original Symbian OS. Symbian was the most popular smartphone OS until the end of 2010, when it was overtaken by Android.