Lego Mindostorms Ev3 Sup3r Car line following program.
You can compile the C# code I propose in this page using Xamarin Studio 5.10.1 (Build 6), with Mono 4.2.1 as active runtime and the Monobrick Firmware Library 1.2.0.39486 to let it work on board the Lego Mindstorms Ev3 with the Monobrick firmware.
The source code is happily shared under the Code Project Open Licence (CPOL) 1.02.
Check out the video at http://www.smallrobots.it/sup3r-car-model/sup3r-car-video/