I have been working really hard towards this day and I am proud to announce that as of today BrewPi is fully open source! Sorry to have kept you waiting for so long, but it just takes so much more time when you are building something that anyone should be able to use compared to hacking something together for yourself.
BrewPi is an open source fermentation controller that runs on an Arduino (for now) and a Raspberry Pi. It can control your beer temperature with 0.1 degree precision, log temperature data in nice graphs and is fully configurable from a web interface.
If you are not into brewing, but do like to thinker with electronics, give the article a read. I had to invent many little things that could be very helpful for other projects too. I can think of a lot of cool things you could that involve controlling an Arduino from a web browser.