Design an Instrument Horn/Bore in the Browser

I just discovered the Example "Simple Oboe" and it's illuminating! It shows how each of the bore holes is chosen to make a specific frequency resonate. Of course I always knew that in the back of my head, but it's interesting to be able to adjust the design

This is in-browser demo of the Openwind library for Python. It is designed to assist designers of musical instruments. It includes acoustic modeling, resonance detection and can even create finger charts!

I am curious how they are running the python code in the browser. But mostly it's fun trying to design tubas and french horns!