GlassFish v2 is an open source Java EE 5 application server built by the GlassFish community
. GlassFish v1 was the first Java EE 5 application server available, with a focus on developer features. The successor, GlassFish v2, adds enterprise class features. GlassFish v2 will be followed by GlassFish v3
, which is currently under development by the GlassFish community and provides a modular, lightweight, extensible architecture.
GlassFish v2 was released September 17, 2007 and is available for download
. The Sun-supported counterpart to GlassFish v2 is the Sun Java System Application Server 9.1
and was also released September 17th, 2007. GlassFish v2 and the Sun Java System Application Server 9.1 offer the same set of features.
This FAQ entry -- How does GlassFish v2 differ from the Sun Java System Application Server 9.1? -- provides a great comparison between GlassFish v2 and Application Server 9.1 and is a must-read if you have any questions about the differences between GlassFish and the Application Server (you won't be alone if you do have questions; this seems to be an area of some confusion).
This article -- GlassFish v2: Open for Business
-- is also a must-read and provides an excellent overview of GlassFish v2.