ZeroTier

ZeroTier is directly connecting the world's devices with universal software defined networking.

ZeroTier One creates virtual LANs that work just like switched Ethernet and is available everywhere. ZeroTier One is useful as a VPN alternative, a private networking backplane for cloud infrastructure deployments, inter-office LAN connectivity, managing specialized devices, or any other application where it's useful to create a secure virtual overlay network that stays up and available even as things move around or physical network topology changes.