For the past few months I've been working on a UAV using a raspberry pi as the flight controller, a crius aiop as the sensor board + real time rate pid controller, an alfa wifi adapter for the remote and HD fpv streaming.
I'm preparing to publish the source code for the whole system soon - it has the flight controller software (the brain), a small firmware for the crius, a ground station/remote and a simulator to test the brain.
The goal with this is to make a smarter UAV with various assists to make fpv flying easier and more fun. Basic things like hold position and altitude, return home, follow me, protection sphere for the user, auto land/takeoff, battery range calculation and point of no return, unlimited waypoints and fence, ground following using a sonar - and more CPU/GPU intensive ones like object tracking, camera stabilization without a gimbal, ground altitude database.
You can check out the build log at http://jeanleflambeur.wordpress.com/
I managed to get this IMU to work with the raspi using i2c:
I'm trying to remove the crius from the setup to simplify a bit. Main goal is to make the quad case a bit smaller using the drotek imu + odroid w instead of the raspi.