I recently discovered three.js, a JavaScript library/API used to create and display animated 3D computer graphics.
Here are some examples what you can do with three.js. It's pure JavaScript, no Flash required!
They all worked smooth on my Notebook (Intel Pentium P6200 processor) with Google Chrome 28 on Linux.
You have to click on the links to see the examples!
Stemkoski
Textures

Three.js

Reflection

Webcam

Motion detection

3D function plotter

HexGL
Solar System

Planet Maker

Demonstration - takes ages to load, but when its loaded it is fast
See also
- stemkoski: Many examples
- Chrome Experiments