I\'ve used the MIT Continuous testing plugin in the past, but it has long since passed out of date and is no longer compatible with anything approaching a modern release of Ecli
There is a list in this Ben Rady article at Object Mentor: Continuous Testing Explained. Unfortunately the only Eclipse tool appears to be CT-Eclipse which is not currently maintained either.
There is also Fireworks for IntelliJ and Infinitest which is not IDE specific but also has some IntelliJ integration.