I need an authoring tool that would allow the writing of a huge series
of computer how-to documentation.  The documentation format is heavily
stylized.  I then want to generate three versions of the content:

a PDF version for printing and publishing
an e-book version compatible with all popular e-book readers
a video version of some DRM friendly format

OpenOffice Writer claims to support WYSIWYG editing of DocBook XML,
but in practice this feature is not usable.  My XML format will
include some components like DocBook but will need to be much more
robust and extensible.  Can OpenOffice be customized to provide
WYSIWYG editing of custom XML?

What tools provide the simplest means for:
	-defining my own XML Schema that includes tags for each of the three versions
	-allow editing of XML tags specific to one version without disrupting the others
	-define my own custom WYSIWYG editing rules based on XSLT and XHTML
(for the PDF version)
	-define my own custom WYSIWYG editing of the ebook format?(is OeBPS
right for this?)
	-give me the flexibility to later generate a multimedia video version
from the same XML content

I would prefer a Java friendly tool but any solution that is tested
and proven is fine.

I would also prefer something compliant with open standards, but
again, the solution must be well proven, not some open source
vaporware feature.

I noticed Adobe FrameMaker claims to have some of these features, but
there is no clear documentation of how (or if) it could be used for
the above requirements.

If no available tools meet these requirements, an explanation of what
Java/XML architecture should be used to develop an in-house product is
also an acceptable answer.