Browser Hardware Acceleration

Firefox is #-Link-Snipped-#tomorrow. I'm going to be one of the first ones to download the browser. I've always wondered how the browser hardware accelration works. From my little understanding of hardware, I'm guessing that if we play any graphic intensive game or app via our browser (possible via HTML5) then the browser will hand over the graphics calculations to the GPU, so that CPU will be free to do the tasks its meant to perform.

The question I wish to ask is does hardware acceleration work on compuer machines that don't have GPU?