Drum machine patch I've been developing in Max/MSP. Everything is entirely synthesised and lovingly developed by yours truly. Right now it contains:
~ A kick, snare, open hihat, closed hihat, and noise hit
~ Presentation view interface that offers greater customizability over each percussion sound. Using it, you can edit filter parameters, pitch envelopes, amplitude envelopes, etc.
~ A 1-to-2-measure long sequencer with customizable BPM
~ A master and multi-track recording interface
Most of this is loosely based on the 808 architecture, but I've also drawn inspiration from the Synth Secrets articles from old Sound on Sound magazines, Sweetwater articles, and any song where the percussion makes me go "damn, OKAY!!!". Next update I do to this, I'm going to implement a random delay option on the sequencer so it sounds more organic, add some form of preset functionality, add a distortion effect to the kick, and most likely overhaul the hihat architecture. I'm not the biggest fan of how it sounds right now.