I'd love to hear more about what technology was used to make this. I actually have a web port of my DX7 emulator, but I don't promote it much. I've also been experimenting more recently with a Rust code base for synthesis and am considering picking that up again.
This is pretty neat! Fatigued after so many "this vs that" framework talk nowadays, very refreshing to see someone just using what they feel comfortable with and building an all around awesome project.
Just honest high-quality craftmanship and lots of fun :) Props to the creator.
The JS source is pretty readable; looks hand-coded and lightly minified rather than targeted by some other language, a little help from jQuery and jQuery UI.