The Application Switch sits between applications and service providers, allowing a central location for configuration instead of requiring the user to configure each application separately. The switch also allows mutliple services to be combined and appear as a single service to applications.
OpenEJB is a simple, lightweight Enterprise JavaBeans (EJB) container and server. You can embed OpenEJB in your own applications, or in a Web application server like Tomcat, or run it as a standalone EJB server. It supports EJB 3.0, 2.1, 2.0, and 1.1, and has partial support for EJB 3.1.