Their clients consist of a daemon and, optionally, a GUI. The daemon is open source. The Android and Linux GUIs are open source but the Windows, iOS, and macOS

Their clients consist of a daemon and, optionally, a GUI. The daemon is open source. The Android and Linux GUIs are open source but the Windows, iOS, and macOS GUIs aren't. Source: https://tailscale.com/opensource/ https://tailscale.com/opensource/