The Web Developer's Library contains information about designing and developing usable widgets.
Introduction to S60 Web Runtime environment—An overview of widgets and the Web Runtime environment that enables widgets to run on S60 mobile devices. The section lists the supported standards and features, includes version history information, explains how widgets behave on mobile devices, and discusses security aspects.
Designing widgets—Guidelines for designing usable widgets. Where relevant, links are provided to the Web Runtime API reference and documentation on the Web.
Laying out pages—Guidelines for developing widgets for specific audiences with a simple and clear design that helps make the most important content obvious.
Designing for mobile devices—Guidelines for designing widgets that look good on small screens and on different screen sizes and that adapt when the screen orientation changes from portrait to landscape.
Porting widgets—Summary of changes that you need to make manually when porting a widget from a desktop environment to the Web Runtime (WRT) environment of S60 mobile devices.
Managing user interaction—Guidelines for designing user interaction methods for devices with the five way navigation keys or touch screens.
Moving within widgets—Guidelines for choosing navigation methods.
Designing for limited resources—Guidelines for using images and scripting effectively, keeping response times short, saving battery time, dealing with network issues, coping with the processing limits of the devices, and retrieving data.
Developing widgets—Detailed information on how to implement the widget functionality. Where relevant, links are provided to the Web Runtime API reference and documentation on the Web.
Getting started with widgets—Instructions for developing widgets. The section lists the environment and tool requirements for developing widgets, lists the steps to create a widget for an S60 mobile device, and describes the files that a widget consists of.
Using platform services—Instructions for creating widgets that use the S60 Platform Services.
Supporting multiple languages—Instructions for localizing widgets to support multiple languages.
Testing your widget—Instructions for testing your widget after you have created it.
JavaScript console—Instructions for using the JavaScript console to debug widgets.
Example widgets—Example widgets that you can download to your PC and then to a mobile device or emulator. You can also examine the source files.
Integrating widgets with devices—Methods for deploying and managing widgets on mobile devices.
Deploying your widget—Summary of the various methods you can use to transfer widgets to a mobile device.
Managing your widget on the mobile device—Instructions for launching, managing, and exiting widgets on the mobile device and for creating self-updating widgets.
Web Runtime API reference—API reference for the S60 5th Edition.