OpenConnect - VPN client compatible with Cisco AnyConnect SSL VPN
OpenVPN Manager - OpenVPN Manager is a tool which controls OpenVPN.
OpenVPN - OpenVPN - The Open Source VPN
Firezone - Firezone is a remote access platform that’s painless to deploy, easy to manage, and built on WireGuard® to be blazing fast. Best of all it's self-hosted and open-source.
WireGuard - Fast, Modern, Secure VPN Tunnel
fruho - fruho is an open-source, zero-configuration VPN manager.