Series 40

Nokia Series 40 Platform, often shortened as S40, is a software platform and application user interface (UI) software that was previously used on Nokia's broad range of mid-tier feature phones from 2002 to 2014, as well as on some of the Vertu line of luxury phones. It was at one point the world's most widely used mobile phone platform and found in hundreds of millions of mobile phones. Series 40 was more advanced than Nokia's Series 30. It was not however used for smartphones (where Nokia used Symbian at the time, and later Windows Phone) and differentiates from them by not supporting true multi-tasking and do not have a native code API for third parties and thus do not support installable applications other than (with few exceptions) MIDlets that are written in Java. However, the simplicity of the system made it more responsive compared to Nokia's Series 60 smartphones. The final Series 40 phone was released in 2013, after which Nokia feature phones switched to a different platform, Series 30+.