Ericsson R380

[1] It combines the functions of a mobile phone and a personal digital assistant (PDA),[2] and was introduced at CEBIT on 1999/2/18.

It predates the UIQ user interface which runs on those later phones, but again, the heritage is clear.

[8] The R380 ran the EPOC Release 5.1 operating system, which can thus be considered the first Symbian OS device.

The user interface (UI) was developed at Ericsson's Software Applications Laboratory in Warrington, UK.

The UI was built using an in-house developed library called the Ericsson Control Kit (ECK).