Kevin Fisher <kgf at golden.net> writes:
> For any Xanadu fans out there, I just stumbled across this:
> 
> http://www.night.dircon.co.uk/abora/index.html
> 
> It is a preliminary implimentation of the Udanax-Gold specification in
> Dolphin Smalltalk (wonder how easy it would be to port to Squeak?).

It's still very early days for Abora, but there is enough support for
transclusions and links built from them to start to get a feel for how
the core of the system works.

I'm currently working on a client/server split, and then I'm expecting
to circle around to flush out the UI a little and link into a
more reasonable persistence mechanism.

If I can keep the ball rolling then I intend to get the server side
working on a cross platform open source smalltalk, probably Squeak, but
a need for performance may widen the field. I doubt if I will
translate the front-end to another smalltalk, but intend the front-end
API to be language (smalltalk and below) neutral.

The source is available as Dolphin packages, which I believe are just
text files. Still it is probably too early to try and do anything much
with it, on the plus side there are test cases, but there are also a
few 'danger' methods and gaping holes that currently limit performance
and generality.

I'm not sure if there is a Udanax-Gold spec, but as much as I can
understand I'm trying to put into Abora. I'm hoping to put together a
technical document of my limited understanding of Udanax-Gold and how
it is implemented in Abora that should prove interesting to others. 
There is also some work centred around the http://www.sunless-sea.net site to
translate/publish other technical documentation from the original
Udanax-Gold project.

> The fascinating part is the example--you can open an Ent Inspector
> on an example document "tree".  It's nice to see some of this theory
> I've been reading about in actual practice!
> 
> (sadly it is Windows-only :p, but neat nonetheless!)

The trees are kind of neat, though they don't provide an immediate
visualization of the sharing of the tree nodes between versions of the
same document. They also skip the lower  ContentElement level.

There still seems to be a lot of interesting stuff in the Udanax-Gold
system, both for hypertext systems but also for versioning and sharing
of data stored in trees (eg BOMs). Hopefully this and other work will
help to push some of the still relevant ideas out into the open a
little more.

Abora is available under an X11 licence, and I mean to set up a
project on sourceforge for it once it can stand on it's own legs a
little better.

I welcome any suggestions, ideas, or help. It's a little way off, but
I will be attending OOPLSA if anyone would like to learn more.
-- 
David G Jones               mailto:david_jones at night.dircon.co.uk
                                    http://www.night.dircon.co.uk
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