Technology
Headscale: the free alternative to Tailscale
Headscale is an open-source reimplementation of Tailscale's control plane, so official Tailscale clients connect to it unmodified. Version 0.25.1 stabilises HuJSON ACLs, advertised routes, and DNS across large meshes. Running it takes a Go binary, SQLite or PostgreSQL, and a reverse proxy terminating TLS. SSO, Funnel, and analytics remain better commercially.