Everything in Tailscale is Open Source, except the GUI clients for proprietary OS (Windows and macOS/iOS), and the control server. Headscale [1] allows one to

Everything in Tailscale is Open Source, except the GUI clients for proprietary OS (Windows and macOS/iOS), and the control server. Headscale [1] allows one to implement a self-hosted, open source alternative to the Tailscale control server. [1] https://github.com/juanfont/headscale https://github.com/juanfont/headscale Almost all of tailscale is opensourced at this point besides the GUI.