Software
Windows 10 or 11 is required.
SkyPilot
The client for Microsoft Flight Simulator 2020 and 2024, X-Plane 11 and 12 and Prepar3D v4–v6: network connection, flight plan from the website, messages, nearby controllers. It finds the running simulator by itself.
MSFS 2020 / 2024 X-Plane 11 / 12 Prepar3D v4–v6
X-Plane: copy the XPlanePlugin/SkyPilot folder from the SkyPilot folder into X-Plane/Resources/plugins. To see other pilots, add a CSL model package to it, for example the free Bluebell (see CSL-README.txt there).
Download SkyPilotNetwork-ATC
Radar: EuroScope and .natc sectors, handoffs, SID/STAR, departure and arrival lists, STCA, plugins.
Download Network-ATCRadio voice is built in
Both programs talk on the radio themselves: nothing else to install. Choose the microphone, speakers and push-to-talk key or joystick button in the settings. You hear stations tuned to your frequencies within radio range; weak signals sound noisy, as on a real VHF radio. The voice server uses UDP port 3782.