Free and/or Open Source Software
jMock
JMock is the leading mock objects library for Java. Mock objects help you design and test the interactions between the objects in your programs. JMock makes it quick and easy to define mock objects, so you don't break the rhythm of programming, lets you precisely specify the interactions between your objects, reducing the brittleness of your tests, works well with the autocompletion and refactoring features of your IDE, plugs into your favourite test framework and is easy to extend.
Hamcrest
Hamcrest is a Java library that lets you define matching or validation rules. Originally part of JMock, Hamcrest is now an independent project and has been adopted by several projects, including the latest versions of the JUnit testing framework. It is used to specify subscriptions and advertisments in Babble.
SceneBeans
SceneBeans is a Java framework for building and controlling animated graphics. It removes the drudgery of programming animated graphics, allowing programmers to concentrate on what is being animated, rather than on how that animation is played back to the user. Its component-based architecture allows application developers to easily extend the framework with domain-specific visual and behavioural components. It is used in the LTSA tool to animate formal models of concurrent systems.
Team Piazza
Team Piazza is a build monitor plugin for the Team City continuous integration server. It provides a public display of the integration state of the software under development, alerts the development team when integration errors occur and ensures that the software being developed always remains in a deployable state. The use of portraits encourages personal involvement in and shared ownership of the software's quality.