There is also PIT which can be hooked into your build via a maven plugin or command line interface.
It provides much nicer reports than the other available tools with combined mutation and line coverage. It also runs considerably faster than the source based tools for Java such as Jester, and about twice as fast as Jumble.
Unlike the Jumble and Javalanche it also works with all the major mocking frameworks (Mockito, JMock, EasyMock, PowerMock and JMockit).
(disclosure I’m the author).