As I (the author of docbook2X) have limited time, I necessarily have to give higher priority to certain items when implementing. If you would like to see a certain feature/fix quicker, please tell me. Even better, send patches.
docbook2texixml should be smarter in selecting nodenames when they conflict. The best way is to simply prepend the parent's nodename (old behavior in docbook2texi and already implemented in docbook2texi-xslt). I'm just too lazy to implement it.
Fix. texinode_create
Do localizations for docbook2texixml. Perhaps steal from Norman Walsh's stylesheets.
Fix. add stuff to %docbook2texi::user_str and copy the logic used in docbook2manxml to get_user_str.
Internationalization requires that we set @documentlanguage every time the lang changes. We could do it the right way, which takes a lot of work on the existing code base), or do it the “wrong” way, which is to insert a non-standard element to signal document language change. The latter, however, requires yet another traversal of the source tree (plain slow) and keeping state.
Anyway, Texinfo internationalization is simply not well-implemented, and the XSLT stylesheets will solve the problem correctly, so this probably will never be implemented for docbook2texixml.
docbook2X drops nested inlines in the source since I mistakenly thought that Texinfo does not support them. Might also want to defined Texi-XML clearly so we don't allow nested markup which Texinfo or texi_xml cannot reasonably support.
Fix. Check all instances of get_inline_inline calls and replace the ones that may nest with calls to tr_inline_container. Note that the two functions are used differently.
Write the DTD and documentation for Texi-XML.
There are still some Texinfo commands that are not exposed in Texi-XML but are still generally useful for SGML/XML transformation.
Complete SDATA mapping for docbook2man-spec.pl. There are various tables floating around that can be used.
qandaset numbering and toc
Table support is already very reasonable given Texinfo's limitations, but the stylesheet needs to warn the user about the many unsupported attributes. Also column spanning is not supported.
classsynopsis support.
In a few places internationalization is not done properly.
Title page support (also need to extend Texi-XML!)
Remove cruft left from stuff we don't use in Norm's stylesheets.
Merge applicable changes from newer versions of Norm's stylesheets (stylesheet was based on version 1.14).
Translators: port or write new localizations.
Write more documentation on the stylesheets and be able to easily extract it.
The code should try its best to not ignore unexpected elements, invalid or unsupported markup. Even if the implementation is wrong, then at least the user knows about the problems instead of having silent transformation errors.
The XSLT stylesheets have no problem here.
The code needs to be better documented, since these are stylesheets and it is very likely people with their own documents want different styles for them.
Thanks to Norman Walsh's XML jref document type, the XSLT stylesheets have a good start on the documentation.
Collect more DocBook documents to use as testcases.
Some sort of XML-based language for sequential transformation: event-based XSLT-work-alike. Non-trivial.
Get a C++-based XSLT implementation working so that the world does not need to see ugly XML::DOM::Map-based code again.
A SGML-to-XML convertor that is smarter than SP's sx. It may be DocBook-specific and insert the correct document type declaration.
Catalog resolution, or at least redirect recognized DocBook DTD URIs to a local DTD.
Someone contribute Makefiles to do automatic install. (!)