Finite state machines (FSMs) represent a very simple yet widely used formalism. They are used to model simple protocols or even complex systems in an abstract way. Java classes often behave like FSMs. For these reasons, FSMs are often used in conformance testing, which consists in checking that a real implementation conforms with its specification given in terms of a FSM. In this paper, we show how Eclipse- related technologies, like GMF and PDE, can be used to build an editor and test generator for FSMs. We present a complete environment which contains: (1) a graphical editor based on a meta-model for FSMs, (2) an extensible framework for test generation from FSMs according to several coverage criteria, and (3) an API that can be used to test Java classes against their specifications given as FSMs.