OpenHD
OpenHD is an open source digital FPV system for UAVs. It sends low-latency video from the aircraft to the ground station, and can also carry telemetry and control data over Wi-Fi based radio hardware.
OpenHD FPV is useful when you want a configurable digital video link instead of a closed FPV system. A typical setup has an air unit on the drone, a ground unit connected to a screen or computer, and software for viewing video and telemetry.