Eclipse is a kind of universal tool platform - an open extensible IDE for anything and nothing in particular. The real value of Eclipse comes from tool plug-ins that "teach" Eclipse how to work with things - java files, web content, graphics, video, etc. Eclipse allows you to independently develop tools that integrate with other people's tools seamlessly.
Abbot is a framework for testing Java GUIs. It lets you launch an application or GUI component, play back user actions on it, and examine its state. Tests may be coded or scripted. The editor supports recording user actions into a script, exploring the component hierarchy, running the script, and other features you'd expect from a script editor. Test scripts are JUnit extensions.
Eigenbase Resource Generator (ResGen) generates wrapper classes for Java resource bundles. The generated classes contain a 'get' method for every resource string, with parameters appropriate to the parameters embedded in the resource string. If the resource is some kind of exception, it also generates a 'new' method to create an instance of that exception. C++ generation is also supported.
SILGraphite (formerly OpenGraphite) is a project within SIL's Non-Roman Script Initiative and Language Software Development groups to provide extensible cross-platform rendering capabilities for complex non-Roman writing systems. It consists of a rule-based programming language, Graphite Description Language (GDL), that can be used to describe the behavior of a writing system, a compiler for that language, and a rendering engine that can serve as the backend of a text processing application. SILGraphite renders TrueType fonts that have been extended by means of compiling a GDL program. It is currently being integrated into Gecko/Mozilla through the SILA project, a GNU/Linux port is also underway, and there are plans for OpenOffice.org and Abiword integration.