Collection of online javadocs for many popular packages. Includes search and user contributed notes.

Includes study material for Java certification, a discussion forum and articles geared towards Java beginners.

Collection of resources about Java, Jini, the JVM, and object oriented design. Includes articles, books, tutorials, FAQs, discussion forums, applets, source code, and seminars.

Bill Pugh's collection of resources and a mailing list.

Portal with newswires, tutorials, large resource directory, events, and jobs.

Tips, resources, and monthly newsletter on improving the performance of applications.

Applet and tutorial directory, with news and links to other resources.

Collection of links to articles, tutorials, and FAQs.

Collaborative database of reviews about resources.

A directory of open source software focused on Java.