[ravenstine]

The thing that disappoints me about Openstax is that, while they're free/libre, they don't seem to be open source anymore. They used to provide access to the raw XML (CNXML) used to generate the books, but I can't find that anywhere.

It would be nice if there was something like OpenStax, maybe even a fork of it, that could be held in a Git repo and anyone could make pull requests.

[empyrical]

It looks like they're transitioning/have transitioned to editing the books with Google Docs:

https://openstax.org/blog/saying-goodbye-cnx