zpub is a server to collaboratively work on DocBook-based documentation. Editors modify the XML sources with their preferred editor and submit their changes via Subversion. zpub renders the files centrally to various output formats, optionally notifies other editors, provides an archive of all previous revisions of the document, and supports a simple sign-off workflow. The documentation and user interface is currently only available in German.
The Cainteoir Engine is a library for reading and recording different document formats (ePub, HTML, MHT, RTF, email, and others) to various audio output formats (such as PulseAudio, WAV, and Ogg/Vorbis). It also provides the following command-line tools: cainteoir, a front-end to the Cainteoir text-to-speech library; metadata, which extracts metadata from documents to RDF tuples; and tagcloud, which generates tag clouds and tag cloud data.
mdepub is a tool that allows you to compose a book in Markdown format and use Pandoc and Calibre to compile an Epub package including all of the book's source material. In effect, you can keep the source and product in the same file in your library; if you ever want to revise the product, you merely need to extract the source, make edits, and recompile.
The DocBook Authoring and Publishing Suite (DAPS) provides a tool set for easy creation and publication of DocBook sources on Linux. It lets you create HTML (including Webhelp), PDF, EPUB, man pages, and other formats with a single command. It automatically takes care of validating and filtering (profiling) your sources and automatically converts images into a format best suited for the output format. You can easily create profiled source tarballs for translation or review. DAPS supports authors by providing linkchecker, validator, spellchecker, and editor macros. It is well suited to manage large documentation projects with multiple authors using the DAPS docmanager.
osis2epub is a a program that converts a Bible text stored in Open Scripture Information Standard (OSIS) format to an EPUB book. The resulting eBook can then be read on various eReaders or converted to another format. Conversion to a simple text format and to a collection of HTML files with an accompanying stylesheet and file list (for direct viewing or subsequent conversion) is also supported.