Software is tailored upon the MultiWii Flight Controller code.
MPU-6050 Accelerometer Gyroscope Unit
You can build your own Quadcopter flight controller using ready made open source code from open controllers such as this one MultiWii and using easy embedded systems platform like Arduino.
You can then make use of the ease of code and the less expensive components.
And this is sure an educational experience that makes you aware of all Quadcopter principals.