A web based finite state machine editor and simulator created to support Informatics 1: Computation and Logic at the University of Edinburgh.
With the tool, you can easily create and simulate finite state machines in your web browser. There is also support for exporting SVG images. There is also a series of interactive excersises that provide an introduction to FSMs and regular expressions.
Instances of the Workbench can be found on the Informatics Homepages server and on my personal site.