Digging further, this has been shown before in 2020:

https://news.ycombinator.com/item?id=23337091

The author mentions in the thread that he eventually plans to have a proper license for it and needs to figure out the licensing of some of the dependencies, but that was six years ago.

https://news.ycombinator.com/item?id=23338538

This is not directed at the quality of the project itself, however, which seems to be good.

Author here. License is pretty much do whatever you want with it (free as in free information and free beer), I suppose the closest one to that would be MIT, but I don't like its serious legalese tone. I prefer the whimsical "free as in..." phrase