After spending 10 min. creating a site, source code is available
here. Be warned, the program is still in an alpha stage, and has a tendency to crash if you give it invalid input (such as an axis control without telling it which axis). This will be fixed within the next few days when I release the final version.
Again, I'm looking for features you think would be useful, both for teaching newbies and for not having to re-write the same code year after year.