Tailscale is almost open source with Wireguard itself being open source. - Most of the clients are open source probably. - Tailscale allows you to run custom

Tailscale is almost open source with Wireguard itself being open source. - Most of the clients are open source probably. - Tailscale allows you to run custom control server of your own. - One open source control server "headscale" is sponsored by Tailscale themselves.