Jax Systems: DocJar:
- Open Source Java code search engine. Browse Java documents and source code. Includes a free Eclipse plug-in to allow users to browse the site from their Eclipse IDE.
- http://www.docjar.com/

Help4j
- Repository of code examples from open source projects, tips, links and utility classes organized by Java method and class. Windows and Unix/Linus versions. Integrates with JavaDoc.
- http://www.inventivio.com/help4j.html

Java Glossary
- Roedy Green's glossary of Java-related terms.
- http://mindprod.com/jgloss/jgloss.html

Java Gotchas
- Tricky parts to the Java computer language - quirks, features and nasty surprises, and how to get around them.
- http://www.mindprod.com/jgloss/gotchas.html

The Java Home of Kaan
- The Java Scratchbook and shortcuts : code samples and examples sorted by package names. Java Certification programmer exam questions and answers. JDBC/ODBC connection with MS Access. Terras Game. Topics Deployment Directory Services (Dutch). Quality Pro
- http://home.tiscali.nl/~bmc88/index.html