Have you looked at Roberto's awesome Reef Angel controller and thought "Man that's just not complicated enough" or "Gee I wish the firmware were written in C instead of arduino sketches?" You have? Really? I thought I was the only one crazy like that.
Roberto was kind enough to provide me some boards before the cases were ready and I've been implementing my own software for it. It's coming along nicely and I'm talking to most of the hardware except the PH probe and the external flash. The only reef controller functionality it has at the moment is some hard coded hysteresis based temperature control.
I'm posting all my source code at: http://github.com/konkers/reefdemon
If you're still reading, come along for the ride on this hair brained journey of mine.
Woops I would watch out using that name, Reef Devil is a trademark of ETSS.
Other then that it's cool to see other software written. I can't wait to try them both out (When mine arrives).
Doh.... guess I should google first... renamed the project to reef demon
It's doubtful they'd even notice but just in case it was a good idea to change it 
And what's a new project without a logo:

Simple and elegant, I like it
Now make a 468x60 pixel banner 
Nice 
This is why I love the bay area! We have so many smart reefers! 
Quick update. The software is fleshing out into something resembling a reef controller. I have it controlling the temperature in my test "tank" (a bucket of water with a heater and a pump.) I can control the temperature to ~ 0.13 degrees C (~0.24 F.) With moving the control to a PID algorithm, I should be able to get that much tighter.
Here a snapshot of the screen. The blue background of the graph is solid in person but had interference on my phone's camera.

Very nice. What other features do you plan on "building" (coding) in?
Here's a photo of my development setup:
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40g Stretch Hex