2. XBook and DocBook

Yes the "Book" in XBook has some connotation with similar tools called DocBook and StyleBook (used internally in Jakarta Apache projects). There are important differences however with DocBook that may make you decide (not) to use XBook.

DocBook is extremely powerful but at the same time also has a steep learning curve (see e.g. the 648 page O'Reilly Book on DocBook. In my projects I needed a lightweight tool in which I could use and add simple DTDs with just a few tags to learn. In addition I felt the need to integrate and organize other types of documentation (Javadoc, text files, HTML files) possibly generated by other tools like JavaDoc (maybe even DocBook in the future!) and generate an entire navigational site.

In addition I needed a way to extend and reuse both DTD and XSLT stylesheets.