Version 1.3.1 of the Java 2 SDK, Enterprise Edition ("J2EE" SDK) is a
complete implementation of the Java 2 Platform, Enterprise Edition
1.3. The J2EE SDK is intended as a proof of concept and example for
implementations in the application server marketplace. The J2EE SDK
includes a J2EE application server and various tools to help
developers prototype J2EE applications and learn about the J2EE
platform and technologies. It can be used as a J2EE development
enviroment for applications prior to their deployment and
distribution.

WWW: http://java.sun.com/j2ee/sdk_1.3/