WebXOX is a drum machine and sequencer that you can access instantly in browser through the web (for free), creating the sounds entirely in the browser without using samples.
It features four different voices for you to alter, each powered by a single algorithm, with a surprising variety of settings for each voice.
Irritant Creative, the team behind WebXOX, took their cues from classic Roland drum machines. WebXOX is playable in the most recent versions of Chrome, Safari and Firefox. Check it out for yourself from here.