The latest release of Sun Java System Access Manager, version 7.1, is deployable on Sun Java System Application Server (open-sourced as GlassFish) as a single Web application. A recent article on Sun Developer Network, Installing, Configuring, and Deploying Sun Java System Access Manager the Simple Way, describes the process, which takes only minutes to complete. It's a snap.

Also, Sun Java System Access Manager is open source on java.net: OpenSSO. Have a look!