Objavi: the Booktype publishing system
Booktype books are written and stored as HTML, but are converted to PDF and other formats for printing, reading, or further processing. Programs which perform this task are called objavi (pronounced "ob-YAH-vee", as if the J was a Y), after the Croatian word "objavi!" meaning "publish!".
Objavi is free software, distributed under the version 3 or greater of the GNU Affero General Public License. The source is available on https://github.com/sourcefabric/Objavi, which also contains instructions for cloning the git repository.
Objavi is part of the Booktype project which is being developed by the Sourcefabric organization.