Robotics

http://openrov.com/ - Underwater exploration drone
http://www.diydrones.com/ - Drones
http://copter.ardupilot.com/ - Helicopter Drone
http://plane.ardupilot.com/ - Plane Drone
http://rover.ardupilot.com/ - Ground Rover Drone

Projects

http://www.open-electronics.org/ - Electronics Projects

3D Printers