Ted Nelson to Reveal All at Perl Conference
by Michael Swaine July 16, 1999
I was trading e-mail yesterday with the legendary Ted Nelson. Back in
1960, seeing the computer as principally a media machine, Ted-but let
me let him say it-"sought a generalization of media which would bypass
the limitations of paper. My proposal for cross-connecting all media
with two connection types-links and transclusions-is the Xanadu
architecture."
Xanadu is a concept more ambitious than the World Wide Web, and has
been struggling toward realization for decades. Along the way, it has
spawned a number of interesting technologies, among them enfilades,
the Ent, and, quite recently, a product called ZigZag.
Enfilades are a class of data structures and their corresponding
algorithms. Beyond that, I am at a loss to say what they are, except
that they are an important part of Xanadu.
The Ent is a data structure plus algorithms to manage complex
versioning of arbitrary objects with low overhead and great
parsimony. Complex versioning is a feature of Xanadu.
ZigZag is a shareware program that runs on Linux or any platform that
supports Perl 5. It is a hyperstructure kit, but you can download it
and figure it out for yourself. It currently has nothing directly to
do with Xanadu, so far as I can tell, but that may soon change.
The subject of our e-mail was the fact that Ted will be speaking at
the O'Reilly Open Source Convention-Perl Conference 3.0 in Monterey,
California, August 21-24. The tentative title of his talk is "Open
Source Xanadu: Enfilades Revealed."
This will be the first public presentation of recent Xanadu internals,
Ted tells me. He will explain, as far as possible in the half hour
he's been given, enfilade theory and the resulting architecture of the
two Xanadu systems that were sponsored by Autodesk during its
ownership of Xanadu. All that code is being made open.
The goal of opening Xanadu source is to get help in creating a new
Xanadu. Ted says, "The new Xanadu is planned to have the old structure
[generalized for net addressing] underneath, ZigZag way underneath as
a general rational programming structure, and spectacular eye-popping
interactive stuff at the top that will change the definition of
interactive text forever."
If you've never heard Ted speak, it's worth going to the conference
for his talk alone. I'll be there.
Oh, the Perl stuff should be interesting too.