Circuit Simulator by Paul Falstad is an electronic circuit simulator. Ported to Pandora by dimag0g.
When the applet starts up you will see an animated schematic of a simple LRC circuit. The green color indicates positive voltage. The gray color indicates ground. A red color indicates negative voltage. The moving yellow dots indicate current. To turn a switch on or off, just click on it. If you move the mouse over any component of the circuit, you will see a short description of that component and its current state in the lower right corner of the window.
http://repo.openpandora.org/?page=detail&app=circuitsimulator.dimag0g.15