Driving Awareness, Adoptions, and Affordability
There's a nice article about this called "Open Textbook Authoring Tools Part 2 – WordPress and Pressbooks" posted Feb. 7. It explains the Anthologize plugin for WordPress, along with Comment Press and digress.it, tools which "added to an emerging vision of WordPress as a web platform for authoring multi-format books in a dynamic, networked way."
Then there's Pressbooks, which has "customized the backend dashboard and interface of Wordpress to suit it even better to authoring books specifically." (See below.)