...Founded and maintained by Dominick Baier and Brock Allen, IdentityServer4 incorporates all the protocol implementations and extensibility points needed to integrate token-based authentication, single-sign-on and API access control in your applications. IdentityServer4 is officially certified by the OpenID Foundation and thus spec-compliant and interoperable. It is part of the .NET Foundation and operates under their code of conduct. It is licensed under Apache 2 (an OSI-approved license). Active development happens on the main branch. This always contains the latest version. Each (pre-) release is tagged with the corresponding version. The aspnetcore1 and aspnetcore2 branches contain the latest versions of the older ASP.NET Core based versions.