github.com/PX4/PX4-Autopilot ↗

About PX4/PX4-Autopilot

PX4 is an open-source autopilot software stack designed for autonomous unmanned vehicles including multirotor drones, fixed-wing aircraft, VTOL platforms, rovers, and experimental vehicles like helicopters and submarines. Built in C++, it runs on multiple operating systems including NuttX, Linux, and macOS, and is distributed under the BSD 3-Clause license. The project is hosted by the Dronecode Foundation under the Linux Foundation, ensuring vendor-neutral governance.

The autopilot stack is built around a modular architecture using uORB, a publish-subscribe middleware compatible with DDS and ROS 2. This design allows modules to run in parallel with thread safety, enabling users to customize configurations by including only needed components. PX4 supports a wide range of hardware through the Pixhawk ecosystem, providing first-class integration with MAVLink protocol and comprehensive tools for simulation (SITL), hardware-in-the-loop testing, and flight log analysis.

The project is particularly developer-friendly with extensive documentation covering everything from basic setup to advanced development tasks. It includes Docker-based simulation that requires no additional dependencies, making it accessible to new users. PX4 maintains an active community through weekly developer calls, Discord channels, and discussion forums, and welcomes contributions from developers of all skill levels.