Here are a list of 10 open source Drone projects. We will work to continuously update this list as & when we find more projects.

Paparazzi UAV (Unmanned Aerial Vehicle) is an open-source drone hardware and software project encompassing autopilot systems for multicopters/multirotors, fixedwing, helicopters and hybrid aircraft.The project includes source-code for the avionics and the ground station computers as well as the hardware designs for many parts of the avionics system. Paparazzi’s avionics software is portable and can be used on varied hardware platforms. The ground station computer software is written in statically typed functional language assuring reliability and stability of the system.

OpenPilot is an Open Source UAV autopilot created by the OpenPilot Community with an aim to be used for civilian and research purposes. It is a highly capable platform for multirotors, helicopters, fixed wing aircraft, and other vehicles . It comes with a complete flight plan scripting language and other powerful features. OpenPilot is currently focused on developing two hardware platforms: the CopterControl (both Original and CC3D) and the Revolution. OpenPilot Revolution is an autopilot platform with a full INS unit onboard, while the CopterControl boards are powerful stabilization boards with 3 axis gyros and accelerometers. The CopterControl boards can be augmented by different sensors and communication systems. Both units utilize the OpenPilot Ground Control Station software where options and setup are done, as well as providing Ground Control functions such as way-point setting and telemetry functions.

ArduPilot (ArduPilot Mega - APM) is an UAV platform, able to control autonomous multicopters, fixed-wing aircraft, traditional helicopters and ground rovers. Ardupilot is an award winning platform that won the 2012 and 2014 UAV Outback Challenge competitions. It is based on the arduino. The ArduPilot project has evolved to a range of hardware and software products, including the APM and Pixhawk/PX4 line of autopilots, and the ArduCopter, ArduPlane and ArduRove software projects.

Erle-brain is an open hardware and open source Linux-based autopilot for drones. It consists of a BeagleBone Black and a PixHawk Fire cape and it comes with a Debian image flashed, ROS pre installed. The hardware has many more peripherals.

The Dronecode Project is an open source, collaborative project that brings together existing and future open source drone projects under a non profit structure governed by The Linux Foundation. The platform has already been adopted by the organizations on the forefront of drone technology like Skycatch, DroneDeploy, HobbyKing, Horizon Ag, PrecisionHawk, Agribotix, and Walkera, among others.Dronecode includes the APM/ArduPilot UAV software platform and associated code.

Mission Planner is a free, open-source, full-featured ground station application for the ArduPilot open source autopilot project. Mission Planner is a ground control station for Plane, Copter and Rover. It is compatible with Windows only. Mission Planner can be used as a configuration utility or as a dynamic control supplement for autonomous vehicles. It can be used to do things like loading the firmware into the autopilot, Plan, save and load autonomous missions into autopilot etc

PX4 is an independent, open-source, open-hardware project aiming at providing a high-end autopilot to the academic, hobby and industrial communities at low costs and high availability. It is a complete hardware and software platform, much like a computer, and can run multiple autopilot applications like the PX4 flight stack or APM

Tower is a Ground Control Station Android app built atop 3DR Services, for UAVs running Ardupilot software.

The AeroQuad is an open source hardware and software project dedicated to the construction of remote controlled four-rotor helicopters, also known as quadcopters or quadcopters. AeroQuad hardware typically consists of the fully-featured STM32-based AeroQuad32 flight controller board or an Arduino microcontroller (Mega 2560 or Uno) as the flight controller board, and an AeroQuad shield with various sensors, such as an accelerometer, gyroscope, magnetometer (heading), barometer (altitude hold) ultrasonic sensors and GPS.

Is an other open source project from 3d robotics. Its a flight controller based on APM:Copter. Its a consumer product developed in concert with the ardupilot core development team and contributors around the world.