[JP] Day 4 - Glassfish

Glassfish is the RI (Reference Implementation) of the Java EE 5 Application Server, which gets developed mainly by Sun in conjunction with Oracle.
So they are using an evolved TopLink for the JPA (Java Persistence API) which is better known as EJB 3.0, although EJB is more than that and the JPA will have live beyond EJB.
Beside being the RI of Java EE 5.0 Glashfish offers two nice features:
CallFlow
+ Profiling
+ Monitoring
+ you can turn it on/off at any time

Grizzly
+ HTTP-Framework
+ uses NIO
+ non-blocking sockets for HTTP-Processing
+ integrates into Tomcat
+ replaces Tomcats frontend and will be handed over to Tomcat
+ a lot faster (between 5 and 500 times) then old I/O-style thread processing