Tunneling

tinc is a Virtual Private Network (VPN) daemon that uses tunnelling and encryption to create a secure private network between hosts on the Internet.

OpenVPN Connect provides flexible VPN solutions to secure your data communications, whether it's for Internet privacy, remote access for employees, securing IoT, or for networking Cloud data centers.

Simple, fast VPN tunnel utilizing state-of-the-art cryptography, minimal codebase for security, supports cross-platform use, offers IPv4/IPv6, and ease of deployment.

fastd is a very small VPN daemon which tunnels IP packets and Ethernet frames over UDP. It supports various modern encryption and authentication schemes and can be used in many different network topologies (1:1, 1:n, meshed).