JOSSO, or Java Open Single Sign-On, is an open source J2EE-based SSO infrastructure aimed to provide a solution for centralized platform neutral user authentication.
* 100% Java
* JAAS-based Transparent Single Sign-On across multiple applications and hosts.
* Built-in with a Pluggable Framework to allow the implementation of multiple authentication schemes and stores.
* Runs in JBoss 3.2.6 application server.
* Runs in Jakarta Tomcat 5.0.27+ .
* Provides Identity information to web applications and EJBs through the standard Servlet and EJB Security API respectively.
* Comes with a Reverse Proxy component that can be used to create n-tier Single Sign-On configurations.
* LDAP support for storing user information and credentials.
* Database support for storing user information and credentials.
* XML support for storing user information and credentials.
* Avalability of a Jakarta Tomcat + JOSSO 1.1 bundle.
* Client API for PHP. This allows to build SSO-enabled PHP applications.
* Standard Based: JAAS, Web Services/SOAP, EJB, Struts, Servlet/JSP.
* Commercial-Friendly. Released under the BSD License.
还有一个项目也是解决单点登录问题的，他是耶鲁大学的一个项目CAS