View online at http://toji.github.io/webgl2-particles-2/
Uses Transform Feedback, a new feature of WebGL 2.0, to simulate 1 million particles.
Demo is based on a mashup of code from http://mrdoob.com/lab/javascript/webgl/particles/particles_zz85_2m.html and http://mrdoob.com/projects/christmasexperiments/2013/, both by the talented Ricardo Cabello (Mr. Doob)
Bonuses: If you have a Leap Motion plug it in and wave your hands around. :) If you have a VR headset and a WebVR-enabled browser, and an input device or gamepad, try it out!