While there are a couple of open-source brushless drivers already available, [neuromancer2701] created his own brushless motor controller on an Arduino shield.

An interesting Arduino project has been published to the Instructables website showing how an Arduino CNC shield and controller has been used to create an awesome 3 axis Arduino CNC plotter.

The High Power H-Bridge Motor Shield for Arduino is equipped with built-in current sensing utilizing the ACS712, and is capable of driving any DC motor up to 15Amp.