Here each particle is a plane using a fragment shader that receives as parameters the color of the particle, and the texture to use for the alpha channel. In each frame we update the ParticleSystem that emits and updates particles; the information of the ParticleSystem is used to update the position of the planes and the values passed to the shader.
The particle system is independent of the rest of the framework and could be use with a 2d-canvas, or even with a DOM based scene.
Inspired in this on-line particle editor (flash) done by Devon O. Wolfgang