In this paper we present the design and features of the Automaton Visualization Applet (AVA). AVA is a tool for creating and editing graphs and automata which provides a friendly user interface. The applet supports finite automata, pushdown automata, Turing machines, and a model based on fractions called Fractran, of which we give an overview. AVA allows the user to perform the actions of the various machines, e.g. testing input strings to see if they are accepted. The applet also supports importing and exporting graphs using eXtensible Graph Markup and Modeling Language[4] (XGMML), an XML language for describing graphs.