DrJava is a lightweight programming environment for Java designed to foster test-driven software development. It includes an intelligent program editor, an interactions pane for evaluating program text, a source level debugger, and a unit testing tool.
VirtualMock is a Unit Testing tool. It uses Junit, Aspect-Oriented Programming (AOP) and the Mock Objects testing approach. Through AOP, it supports features which are not possible with other pure-java mock object frameworks.