BookBrackets is a Mustache.js-powered template for books on the web by Dan McKeown created in March 2015. It was forked from bookScroll, which was forked from the template for Retirement Planning Like a Dinosaur.
Along with Mustache.js it also uses the Materialize CSS library and jQuery to power its responsive table-of-contents left side navigation as well as fonts, and layout tools. An example on Codepen by Joe Watkins was also helpful in building the template.
Book Brackets is (as are MaterializeCSS and jQuery and Mustache.js) licensed under the MIT license [or alternatively Book Brackets is licensed under the GNU GPL v2 or later].
You can see the changes to the project in the changelog.md file and view the markup in the index.html file.
The template includes tags surrounded by double curly brackets {{}} that indicate what would go in that part of the template, for example {{title}} and {{authorURI}}. These fields can be specified by putting data into the BookContent.js file.