I have developed an entirely free and open source multiplayer backgammon service.
You can try it out by visiting https://bgammon.org or by connecting via SSH:
ssh bgammon.org -p 5000
I would very much appreciate help with testing and feedback from anyone who knows how to play backgammon, or is interested in learning. The rules of backgammon are available here:
The password prompt is currently non-functional, and private lobbies are not yet available. Otherwise, the service is ready to test out, particularly the accuracy of the backgammon simulation. Because there are no accounts yet, everyone is logged in as a guest.
A terminal-based client is available, and a graphical client is planned. The terminal-based client is available over the web at the link above. This is accomplished by using GoTTY.
Move pieces by dragging them or by clicking a source space and then a destination space. You may make multiple moves by dragging a checker directly to its final destination.