Programmer's text editor; includes support for dynamic download and installation of new plugins from a central plug in server. Java, XML and JSP source are well supported.
A source code analysis tool. With it, you can edit your source code, display relationships between classes and functions and members, and display call trees. [Open Source]
Gwydion Project's hypercode programming environment for Java supports complex hypertext interlinking, multiple groupings of code, and searching of code and documentation fragments. [Open Source, Public Domain]
Integrated Development Environment for Java, written in Java itself. It provides syntax highlight, automatic code completition, edit-compile-execute cycle. It require JDK 1.4. [Open source]