Here comes an implementation of the core JUnit API (junit.framework + some bits) for running JUnit tests inside the Mauve Harness. As an example I prepared the harmony testsuite a little (I only moved the tests into the gnu.testlet namespace so that the Harness can find it): http://kennke.org/~roman/harmony-swing-awt.jar This is the Swing/AWT testsuite that has been prepared by David and moved into the gnu.testlet namespace. You can run single tests like you are used from Mauve, e.g.: jamvm Harness test.javax.swing.AbstractButtonTest This patch not only allows integration of existing JUnit tests, you can now write new tests in JUnit style if you like. This has some advantages, like having setUp() and tearDown() called, some kind of standard named test methods etc. /Roman