> >>>> "ME" == M Evans <datafeed@[...].net> writes:

[snip]

    ME>  Now the idea: Use DisplayPDF to create a
    ME>  resolution-independent, cross-platform device context API in
    ME>  which to draw user widgets themselves.  The idea resembles
    ME>  Chaco, except that the context also tracks OS events.  (I
    ME>  assume Chaco doesn't do this without help from the host
    ME>  library.)

You might want to take a look at Fresco
(http://www.iuk.tu-harburg.de/Fresco/HomePage.html) and Berlin
(http://www.berlin-consortium.org/).  IIRC they have a similar idea.
I could be wrong though its been a while since I looked at these.

cheers,
prabhu