Nokia Series 40 (S40) is a platform for mobile phones based on the Nokia OS. Series 40 devices all contain ARM processor cores driving a variety of RF technologies, such as GSM, UMTS and CDMA.

Series 40 uses a simpler operating system than the higher end Series 60, 80 and 90 (which are based on the multitasking Symbian OS). S40 devices differ from the Symbian-based platforms in that they do not support true multi-tasking and do not have a native code API for third parties and thus do not support installable applications other than MIDlets that are written in Java. It is primarily because of the former that Series 40 user interface appears to be more responsive and faster than other Nokia platforms, but much slower at running third party applications.

In the past, Series 40 devices have been restricted to smaller displays such as 128x128 pixels. From the third edition of Series 40 (S40 E3), devices with resolutions as high as QVGA (240x320) are now available.

-- 6/29/2008 8:51:16 AM: post edited by justin.