hyper-TeX and standards for client-side extensions

Date: Tue, 25 Jan 94 16:50:30 -0600
From: burchard@geom.umn.edu
Message-id: <9401252250.AA19881@mobius.geom.umn.edu>
To: www-talk@www0.cern.ch
Subject: hyper-TeX and standards for client-side extensions
Reply-To: burchard@geom.umn.edu
Content-Length: 2666
The self-contained nature of the Mosaic solution is an important part  
of its success.  And I agree that slightly fascist efforts are  
probably necessary to keep the Web from splintering into incompatible  
subcommunities (which would be really sad).

However, I think there is at least one *serious* reason to consider a  
client-side extension standard: namely TeX.  For mathematics,  
physics, and other technical disciplines, HTML is just fundamentally  
inadequate (with all due respect to the impressive LaTeX2HTML  
converter).  People in these disciplines have just as much need for  
hypertext as everyone else---for example, references to other online  
papers, or inline images/animations.  What they need is "hyper-TeX".

Now, it seems unlikely that DVI previewing will be built into Mosaic  
any time soon.  Aside from the attendant code bloat, DVI previewing  
requires a lot of external resources (i.e. fonts), which would badly  
break the self-contained model that Mosaic wants to present.

A more realistic scenario is for NCSA and the Web community to define  
a standard interface (analogous to the CGI standard for server  
extension scripts) which allows client-side external viewers to act  
as Hypertext Extensions.

First, such a standard should specify a way for external viewers to  
send URLs back to the WWW browser that spawned them.  Second, this  
standard should allow the viewer to specify whether it wants to  
handle the result of accessing the URL itself, or let the browser  
handle it (to allow external viewers to perform their own inlining).

With such a Hypertext Extension standard in place, it would be  
relatively easy to implement hyper-TeX, since the DVI format already  
supports a system of external references through its \special escape  
mechanism (currently used to inline local images).  The \special  
format could be extended to encompass hypertext anchors, which would  
be displayed visually by the DVI previewer.

I recognize the major dangers of opening up the client side---in all  
likelihood we could just end up with the system incompatibility  
nightmare from which the Web has so far let us mercifully escape.   
But if TeX is going to be accommodated (which I think is necessary  
and inevitable), then we should consciously decide whether it's going  
to be a one-time hack or if we want to take the opportunity to define  
a general extension mechanism.

Paul Burchard	<burchard@geom.umn.edu>
``I'm still learning how to count backwards from infinity...''