An environment variable called J2EE_JAR must be created that points to the installed Java EE jar file. For WebSphere Application Server this should point at %WAS_HOME%\lib\j2ee.jar. For WebLogic Server this should point at %WLS_HOME%\lib\weblogic.jar; however, note the specific post-install step for using WebLogic Server with Eclipse in Using a Server Project in Eclipse. On a number of sites, it may be necessary to have multiple Java EE s installed on any given machine. For this reason, the choice of scope for these environment variables (system wide, through a script file or symbolic links) is left up to you.