Pressbooks is a commonly used publishing and editing tool which gives you the flexibility to import a number of different formats for editing. Pressbooks is an authoring platform built on top of WordPress Multisites (web and blogging), and makes significant changes to the admin interface, web presentation layer and export routines of the regular WordPress install.
Pressbooks allows you to create content once and publish it in many formats including a website, PDF document, EPUB (usable in most eReaders), MOBI (for Kindle readers), and various editable files. During the creation process, Pressbooks is able to import or clone existing textbooks for adaptation. These don’t always come over perfectly and some cleanup has to be done, but it can save you a lot of time and effort to start your project based off something already created so you aren’t duplicating work.
Pressbooks also has a feature that will do automatic Media Attribution; if you enter information about the picture when you first upload it, Pressbooks will automatically generate Media Attributions at the end of each chapter if you have enabled that setting in the theme options. Using H5P, you can embed interactive content into the textbook such as quizzes, clickable timelines, flash cards, and Hypothes.is is a browser plugin that can be used for students to highlight, annotate, and comment on the text.