SNiFF+TakeFive Software
Platform-independent source code engineering with C, C++, Java,....

Java Commander
Java Commander is an IDE for the Sun JDK 1.2.

BeanShell Scripting Language
BeanShell (bsh) is a small, free, embeddable, source level Java interpreter with object based scripting language features, written in Java.

JTest Exam Simulator
Download this software to experience a simulation of the certification test, without actually paying money or turning up at the testing center.

Enterprise Developer - JCertify
Purchase software designed to help programmers study and prepare for the Certified Java Programmer Exam. Free trial!

DocWiz: The JavaDoc Documentation Tool
A visual / GUI tool that allows you to add JavaDoc comments to your source code easily. With DocWiz, there's no need to tediously hand-format tags and comment structures for each method.

Emacs JDE Home Page
An Emacs Lisp package that provides a highly configurable wrapper for command-line Java development tools, such as those provided in JavaSoft's JDK. Menu access to a Java compiler, debugger, and API doc, syntax coloring, auto indentation, compile error to source links, source-level debugging, source code browsing.

Image/J
Image processing and analysis in Java.

Japhar
Japhar is the Hungry Programmer's Java Virtual Machine. It has been built from the ground up without consulting Sun's sources.

Java Clock Maker
Customize your own Java Clock. Use the Graphical User Interface to select the options. No programming required, just copy and paste. It´s easy, it´s fun it´s free.

Java Compiler Compiler (JavaCC)
The Java Parser Generator - Popular LL(k) parser generator, from Sun Labs. It's free, but they don't give out its source code.

Java http server
A basic yet functional web server written in Java. Full source available.

Java-Linux Porting Project
Also known as the Blackdown JDK. The most popular port of the JDK to Linux.