Quokka is a software build system, focusing on reproducible, modular builds with fine-grained dependency management. Quokka is implemented using Java and initially focuses on supporting Java-based projects and tools.

The Panopticode project provides a set of open source tools for gathering, correlating, and displaying code metrics

a free Java code coverage tool

jGRASP is a lightweight development environment, created specifically to provide automatic generation of software visualizations to improve the comprehensibility of software

Simplify your workday with integrated issue tracking for Eclipse

ArgoUML is the leading open source UML modeling tool and includes support for all standard UML 1.4 diagrams. It runs on any Java platform and is available in ten languages.

Ivy is a free java based dependency manager, with powerful features such as transitive dependencies, ant integration, maven repository compatibility, continuous integration, html reports and many more.