What is "glassfish"

Glassfish is an open source application server for the J2EE platform. Its proprietary version is called Glassfish Enterprise Server. Glassfish is free software, being doubly licensed under two free software licenses: Common Development and Distribution License (CDDL) and GNU General Public License (GPL) amended to classpath exception.

Glassfish supports all Java EE API specifications, such as JDBC, RMI, Javamail, JMS, JMX etc. and defines how to coordinate them. Glassfish also supports some specific specifications for Java EE components such as Enterprise Javabeans, connectors, Servlets, portlets, JSF and various web service technologies. This allows developers to create portable, scalable, and seamless enterprise applications with legacy code.