JUnit is a unit testing framework for the Java language.

JUnit is a unit testing framework for the Java language. It was created by Kent Beck, Erich Gamma, and David Saff.

It's official site is http://junit.sourceforge.net

JUnit tasks can be started from ANT with the <junit> tag. JUnit can also be integrated with the Eclipse IDE, allowing the user to easily execute all unit tests in a project.

Sources: Wikipedia, JUnit documentation