Hack-A-Day.io project page: http://hackaday.io/project/3292-arc-reactor
Code is a Webbotlib C project (.prj file) that is built with WinAVR (e.g. AVR Studio 4).
You will need to use the .prj file in Project Designer to generate the various Webbotlib files needed to actually compile the code. You'll want to modify the .prj file to point to the included .brd file as well.
Needs Webbotlib 2.11+.