Tailscale is an overlay Mesh network. It relies on a central login server which then brokers wireguard connections behind the scenes. The tailscale also offers DNS, ACLs and a whole bunch of other bits around the side of just transferring data between nodes.
Tailscale is partially closed source and has developed by a business with paid offerings for enterprise. A bunch of their stuff is open source though, and from their blog https://tailscale.com/blog/ they seem a pretty cool company with a heavy focus on fancy new tech solutions, and with a clear route for funding.
The most notable closed source part of Tailscale is the login server which Tailscale host. Headscale is an opensource implementation of Tailscale which you can selfhost!
Tailscale even acknowledge this on their blog and seem to have a nice relationship with the headscale dev. The main headscale dev is also super polite and considerate towards Tailscale, it’s quite a sweet & wholesome relationship to read about on github.
How do I use it?
Currently running Headscale internally on my main server, deployed via docker compose.