Identity management/SSO solution? [closed]

Question

What are your recommendations for a basic, centralized identity management/SSO service? It must be open source, have a pluggable identity manager (eg: LDAP, DB, openID, etc.) and provide a decent range of API access options (eg: web services, REST, etc.). It must also be clusterable for high availability.

JOSSO? CAS? others?

Answer 1

There are a number of open source SSO solutions, OpenAM/OpenSSO, CAS Server and Shibboleth.

Answer 2

Dont forguet simpleSAMLphp if you looking for SAML support or HybridAuth if you just looking for a SSO library.

Answer 3

WSO2 as described here. It's absolutely free, Java based and integrates with most of services / apps via various protocols or APIs.