Pyjamas contains a stand-alone Python-to-JavaScript compiler, and an Ajax framework and widget set. Using these components, you can write comprehensive applications without writing a single line of JavaScript.

This blog post will attempt to explain how to automatically detect your user’s time zone using JavaScript. If you’re in a hurry, you can skip directly to the demo or just grab the files

A unified user interface system across all popular mobile device platforms, built on the rock-solid jQuery and jQuery UI foundation. Its lightweight code is built with progressive enhancement, and has a flexible, easily themeable design

Useful grid control?

Slippy is a HTML Presentation library written with jQuery, it takes a html file in and plays it in any browser.

Nice tutorial by John Resig on advanced JavaScript programming

Processing.js is an open programming language for people who want to program images, animation, and interactions for the web without using Flash or Java applets. Processing.js uses Javascript to draw shapes and manipulate images on the HTML5 Canvas element. The code is light-weight, simple to learn and makes an ideal tool for visualizing data, creating user-interfaces and developing web-based games.

Using mootools v1.11, this javascript gallery and slideshow system allows you to have simple and smooth (cross-fading...) image galleries, slideshows, showcases and other cool stuff on your website

Timeplot is a DHTML-based AJAXy widget for plotting time series and overlay time-based events over them (with the same data formats that Timeline supports).

Nate over at webgraphics talks about a new feature he'd like to see in Safari: that titles on links should be shown in the rather pretty way that Safari currently shows dragged links: