For those interested, here are some technical details, and limitations, of the simulator as it currently stands:
All units, except for the input units, use the logistic function, with range [0-1] as their activations functions. I might get around to making this one of several options, but for now, I prefer the simplicity.
The default network is a 2-2-1 feed forward network. No patterns are loaded by default.
Exception handling is crude. If bugs occur, please let me know thorugh the Contact page.
There is an upper limit (hard coded) of 5000 on the number of individual patterns. There is no real reason for this, except that this is for teaching, not serious simulation. If you need more, consider a real research-grade simulator.
The original codebase which served as my starting point is still online here.