------------------------------------------------------------------------------
About Symbionts
------------------------------------------------------------------------------

Symbionts are 3rd party open source vendors that may or may not be licensed
under the GPLv2. Nearly all of these are now managed via Composer and thus are
no longer found here, but rather in the /vendor directory.

These additional libraries have their own licensing requirements and, as such,
should not be directly modified by Pressbooks developers.

------------------------------------------------------------------------------

Operative verb is "should," the following libs have been patched/forked by Pressbooks:

* custom-metadata (https://github.com/pressbooks/custom-metadata/commit/98c2aa204a8a1078b3e4f532690b35951641b246)
* pressbooks-latex (https://github.com/pressbooks/pressbooks-latex/commit/33aadff95e0cb944d324d1a77d316a6a2e29d271)

------------------------------------------------------------------------------

If you want to use mPDF instead of Prince XML you must install the Pressbooks mPDF plugin.

+ https://wordpress.org/plugins/pressbooks-mpdf