Keycloak is described as 'Open Source Identity and Access Management for modern Applications and Services' and is a Identity Management Tool in the category. There are more than 25 alternatives to Keycloak for a variety of platforms, including Online / Web-based, Self-Hosted solutions, Windows, SaaS and Linux. The best alternative is FreeIPA, which is both free and Open Source. Other great apps like Keycloak are FusionAuth (Paid), Auth0 (Freemium), Okta (Freemium) and CAS (Free, Open Source).
FreeRADIUS is responsible for authenticating one third of all users on the Internet. Welcome to the FreeRADIUS project, the open source implementation of RADIUS, an IETF protocol for AAA (Authorisation, Authentication, and Accounting).
Gigya is one of the leading social choice for websites, integrating online businesses with the top social networks such as Facebook, Twitter and LinkedIn and consolidating the most powerful social features in a single solution.