There are probably plenty of HTML5 particle systems out there--just pay a visit to old man Google and you'll see (I didn't actually look because I was busy assuming I needed to write my own). The problem with all of those other particle systems is that I didn't write them. Also they probably suck. Again I don't actually know.
How about a quick example:
Say I want a very basic particle emitter that just makes red circles.
var emitter = new thegoldenmule.particle.ParticleEmitter([ new thegoldenmule.particle.Acceleration(0, -0.09), new thegoldenmule.particle.Position(x, y, 10), new thegoldenmule.particle.BasicRenderer(context, 200, 0, 0, 1, 10) ]);
DONZO. Say I want something more sophisticated... A small explosion!
var emitter = new thegoldenmule.particle.ParticleEmitter([ new thegoldenmule.particle.Acceleration(0, -0.09), new thegoldenmule.particle.Velocity(3 * Math.PI / 4, 5 * Math.PI / 4, size / 10, size / 10), new thegoldenmule.particle.Position(x, y, size), new thegoldenmule.particle.Lifetime(1000, 2000), new thegoldenmule.particle.EmissionRateFade(50, 0, 100), new thegoldenmule.particle.ColorTweenRenderer(context) .addColor(0, 255, 255, 200,0.5) .addColor(0.3, 255, 255, 50, 0.3) .addColor(0.5, 255, 70, 0, 0) .addColor(1, 0, 0, 0, 1) ]);
BOOM! Awesome, huh? I think the plugin names are fairly descriptive, so I won't explain what each one does... Also because I'm in a hurry! Grab it on github.