We use the term unbook because it’s very much a rethinking and perhaps “overturning” of the book authoring and publishing process. The unbook process can be anywhere from “completely open” (multiple authors, shared process) to “partially open” (single author with editorial control, with contributions from a user community). My book, Marks and Meaning, is certainly the latter. I retain editorial control over the product and oversee the community. An open book is a category of unbook that’s “open source” in the sense that the content is accessible to anyone and open to authors who wanted to re-mix the book and add enhancements or additional content. FLOSS Manuals is an example of an open book process.