Glassfish is a free-ware application for java applications. Glassfish server is a free-ware, light weight application server for the development and deployment of Java Platform and web technologies based on Java technology. It supports different Java based technologies. extensible core based on OSGi Alliance standards with a web container.It has good easy-to-use administration console. It has a special tool for updates and add-on components. It also supports high availability clustering and load balancing functionalities.