Symbian OS

Symbian OS, originally named EPOC32, is a smartphone operating system which was used by various brands, most notably Nokia. It succeeded EPOC16, which ran on Psion's 16-bit Intel 8086 handheld computers.

Symbian supported various user interfaces intended for different device form factors and feature sets.

Originally it was used on Psion PDAs (EPOC Release 1-5), the first version used on phones was 5.1 (Release 5u) on the Ericsson R380.

List of user interfaces
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