OpenVPN - OpenVPN - The Open Source VPN
WireGuard - Fast, Modern, Secure VPN Tunnel
ProtonVPN - ProtonVPN is a security focused FREE VPN service, developed by CERN and MIT scientists. Use the web anonymously, unblock websites & encrypt your connection.
TunnelBear - Really simple VPN to browse the web privately & anonymously.
Tunnelblick - free software for OpenVPN on OS X and macOS
Psiphon - Psiphon is circumvention software for Windows and Mobile platforms that provides uncensored access to Internet content. Read more about Psiphon.