Javootoo "javootoo.com is the Look and Feel Source for both Java developers and end-users. "
JBook
jCIFS Implementing CIFS in Java
JConfig class library
JDO Central Java Data Objects
JDocs
JDOM
Jess, the Rule Engine for the Java Platform
Jfree.org Home of JFreeReport and JFreeChart
JGraph
JGuru
Jigsaw overview
The JPackage project
JMX (Java Management eXtensions) tutorial
JRoller Free, Java-powered weblogs
JUnit
Keel Meta Framework
KickJava
JavaLanguage Specification
Lessons Learned Doing Java Programming for my Web Site
Linux Java Tips and Hints Page
Java Lobby
Apache Log4j
Making sense of Java
Maven
Media Programming by Bill Day

Introduction to Java media programming

Getting started with Java 2D

Antialiasing, images, and alpha compositing in Java 2D

Image processing with Java 2D

Progress on the media front at Siggraph '98

3D graphics programming in Java, Part 1: Java 3D

3D graphics programming in Java: Part 2, Advanced Java 3D

MegaMek "a networked Java clone of BattleTech"
Message Driven Beans Tutorial
Middlegen
Mining Co. Focus on Java
MyCGIServer Free application deployment
Tor Norbye's Weblog
Object Design Home of Objectstore "Database for the Web"
Oracle Business Components for Java
(EJB)
Oracle SQLJ and JDBC
OpenCMS Open Source Website Content Management System
OSS through Java Initiative
package gnu.regexp; Regular expressions for Java
Patterns Central
Piccolo "Welcome to Piccolo! It is a revolutionary way to create robust, full-featured graphical applications in Java, with striking features such as zooming and multiple representation. Piccolo is an extensive toolkits based on the Java2D API. And best of all, it is free and open source"
PJA (Pure Java AWT) Toolkit
PoolMan Object Pooling Library and JDBC Driver
Portlet Open Source Trading Site
PostgreSQL JDBC Driver Homepage
Processing XML with Java
Online book
Java Programmer Certification Exam And Training
The Java Programmers Source Book
Protomatter open source Java classes
Connection pool, object pool, more.
Java Questions Bank
Java Ranch
RIFE web application framework
The Roller Weblogger
Rules4J rule engine
Separating Java hype from reality
Secrets Of The Masters: Core Java Interview Questions
Serverpages.com"The Resource Directory for Server Side Scripting Technologies"
Servlets.com
JavaSkyline
SpringJava/J2EE application framework

Straight Talking Java mailing list

JakartaStruts

"About Struts" at husted.com

Getting to know Struts

"Strut your stuff with JSP tags"

"Welcome to the Struts Framework"

Sun's Java pages
The Swing Connection
Swing Online book
Swing Labs
Tapestry
TheServerSide.com "Your J2EE Community"
Thinking in JavabyBruce Eckel

Thinlet
"Thinlet is a GUI toolkit, a single Java class, parses the hierarchy and properties of the GUI, handles user interaction, and calls business logic. Separates the graphic presentation (described in an XML file) and the application methods (written as Java code)."

JakartaVelocity

Trails
"Trails is a domain driven development framework in the spirit of Ruby on Rails or Naked Objects"

Wicket web application framework

Working with XML
The Java XML Tutorial