Libre >> "Liberty"
Freedom to do what you want.
Gratis >> "Complimentary"
No cost for good or service, even if has value.
Why write book. Why give it for free. Charging schemes. E.g. PDF, print, screencasts.
Self-publishing -- low quality? Sometimes, just like with the professionally published.
The open source software community has experimented with licensing options and business models.
Writing an open book is one way to contribute to the open source community.
Example books. Some are written with dexy.
For free:
Free in one form, paid in another.
Pay only (most books) Free preview (some books, depends on publisher) Free beta, pay for post-beta
