Auth0 - Auth0 is a program for people to get authentication and authorization services for their own business use.
Spring Security - The Spring portfolio has many projects, including Spring Framework, Spring IO Platform, Spring Cloud, Spring Boot, Spring Data, Spring Security...
Keycloak - Open Source Identity and Access Management for modern Applications and Services.
AdiInviter Pro - The ultimate contacts importer and tell-a-friend system for your website.
JSON Web Token - JSON Web Tokens are an open, industry standard RFC 7519 method for representing claims securely between two parties.
Okta - Enterprise-grade identity management for all your apps, users & devices