The last generally release version of a smartphone OS released (almost entirely) by Nokia before they sold their soul to Windows. Also, the first smartphone OS, by far. Also, for a long, long time and years after iOS the most popular smartphone OS by far.

UI Guidelines:

• Nokia Design & User Experience Library

• Nokia N9 UX Guidelines from Nokia. Seems to be oriented to developers, and none of the tools are re-usable templates, but lots of design examples. Check the other tabs as well.

• Nokia Mobile Design Patterns A series of articles, approaching a pattern library. Note that some of these may be very familiar, as it is a wiki, so some older patterns from this book and other information posted to the wiki have been copied to here by the authors, and other users.

• Forum Nokia Design Portal PDF.

• Symbian UI Wiki

• Nokia Series 40 UI Style Guide

• S60 Visualization and Graphic Design Guideline PDF.

• Symbian^3 UI Style Guidelines PDF.

• Nokia Asha UI Guidelines An intro to the Asha UI... but I am pretty sure that this ended up being just "Touch and Type" S40, so the Asha name is not important for UI design/development now.

Stencils & Templates:

• Templates for smartphones meaning S60 3rd and 5th edition, Symbian ^3, Maemo and some newer S40 devices.

• S60 Wireframing Stencils S60 (through 5th edition) elements of all sorts. (Illustrator, Fireworks)

• Templates for mobile phones meaning mostly S40 featurephones, but also some older S60 devices.