English musician Colin Robinson, mastermind o one-man band avant-garde act Jumble Hole Clough, made a software version of The Rhythmicon, the first drum machine. He posted a demo on YouTube:
The Rhythmicon was the first electronic drum machine, invented by Henry Cowell in 1930 and built by Léon Theremin in 1931. More than a drum machine, it was a polyrhythm generator. It was said that the Rhythmicon was wonderful in every respect, except that it did not work.
I have made a quick and dirty soft polyrhythm generator based on the Rhythmicon, using Mixcraft 8.1 Pro and a Novation Launchpad Mini. Here's a short demo.