Design quantum circuits and retrieve actual quantum state.
QCircuit is an aid for understanding, designing, and simulating quantum circuits. You essentially drag-and-drop gates into place on a set of "wires" and see its effects. It currently includes the Hadamard and Not, CNot, and Toffoli. You can feed input bits in one end of a circuit and watch the values change as they continue through the circuit, as well as retrieving the actual quantum state at any given point.