GlassFish 는 응용서버(Application Server)이다.
모듈화, 가벼우며, 확장성있는 구조를 가진다.

아래 사항들을 목표로 한다.

• An open, modular, extensible platform
• A fast, easy, reliable application server
• An enterprise-ready application server with massive scalability and sophisticated administration
• Product updates and add-ons through the industry-strength Update Center 2.0
• Support for OSGi
• Support for dynamic languages such as Ruby and Groovy
• Support for Java EE 6

참조: http://wiki.glassfish.java.net