I believe music21 uses lilypad? I'm sure there's some sort of python + abcnotation thing (I'm obviously not the right person to ask).
I actually don't know if I'll ever want to build/code anything. I sort of think it's clutter and pointless.
It's fidget spinning, no one would care if most of it went away.
In fact it might be more beneficial if most of it went away lol