Here are some links to annotation mechanisms.
http://www.w3.org/2001/Annotea/
""".. we use an RDF based annotation schema for describing annotations
as metadata and XPointer for locating the annotations in the annotated
document."""
(AFAIU using XPointer means that you don't have to do something special
in your DocBook file (eg. maintain ids on all elements) in order to
accommodate annotations)
Everything Ka-Ping Yee does is worth studying closely. His Crit is the
first public annotation system for the Web. It also doesn't require
anything to be done on the side of the document to be annotated. It's
oriented toward HTML, but if you have a browser that can display XML,
I guess Crit could be adapted to work with it.
http://zesty.ca/
http://crit.org/
Comparative overview:
http://www.math.grin.edu/~rebelsky/Blazers/Annotations/Summer1999/Papers/survey_paper.html
--
Jean Jordaan
http://www.upfrontsystems.co.za
