Octavian is a set of JavaScript utilities for working with musical notes, frequencies, and intervals. It is for the moments when you want code to understand that A4 means something more specific than “a string with two characters in it.”

This one scratches a very particular itch: music theory is structured enough to model, but human enough that you immediately run into naming, enharmonics, and the tiny lies we tell ourselves so notation remains usable. Honestly, that is most software if you squint.