There is a fantastic new 3D JavaScript API available aptly named ‘three.js’.
From the ‘three.js’ website:
The aim of the project is to create a lightweight 3D engine with a very low level of complexity — in other words, for dummies. The engine can render using <canvas>, <svg> and WebGL.
You can try some of the excellent demos to see the power of 3D in your browser – use Firefox 9, Safari or Chrome for the best performance.
Some of my favourites:
