SuperTokens is an open source alternative to Auth0. Add secure, hassle free authentication to your app in 1 day. SuperTokens enables startups to launch quicker and focus on their core product offering.
privacyIDEA is an open-source modular authentication system. Using privacyIDEA you can enhance your existing applications like local login, VPN, remote access, SSH connections, access to web sites or web portals with a second factor during authentication.