The Asha 305 and Asha 311 models are known as the first generation of Asha Full Touch phones; the second generation is the Asha 50x line. All devices up to the Asha 50x series run the Nokia domestic operating system with Series 40 UI platform, also known as S40. The Asha 501 (released in May 2013), Asha 500, Asha 502, Asha 503 and Asha 230 (announced on 14 February 2014) are powered by the Nokia Asha platform, which builds on S40 and Smarterphone.[7][8]