A canvas-based horizontal slider that would almost sway me from thinking thumbs up, thumbs down is the best rating UI mechanism.

"D3 allows you to bind arbitrary data to a Document Object Model (DOM), and then apply data-driven transformations to the document. As a trivial example, you can use D3 to generate a basic HTML table from an array of numbers. Or, use the same data to create an interactive SVG bar chart with smooth transitions and interaction."

An isometric painting tool... like painting with a really primitive lego set. :-)

A Javascript drum machine. Apparently works in IE6 but I haven't tried it there. For the HTML5 nerds -- the visualizations are done with canvas.

In-browser IDE written with SproutCore. One of the project maintainers prompted a lengthy discussion on #whatwg concerning bits like contentEditable and painting text to <canvas>.

"As it happens, browser technology (as far as the <canvas> element goes at least) has not moved on one jot in the last two years, so I was able to dust off the Canvastastic codebase and found it still pleasantly usable and not too affected by code rot."

A *much* better <canvas> plugin for Internet Explorer - based on Firefox's <canvas> implementation

"Mocha UI is a web applications user interface library built on the Mootools javascript framework. The Mocha GUI components are made with canvas tag graphics." Man does IE look stupid for not support canvas.

"The images below are the kaleidoscope output, the original image, the original image drawn on a canvas as a pattern, the slice of the pattern, and the slice with mirror symmetry."

"CAKE is a scenegraph library for the canvas tag. You could say that it's like SVG sans the XML and not be too far off. This page is a showcase of CAKE feature tests."

canvas test case