Re: PDF vs Markup Languages

From: Arthur Smith <apsmith_at_APS.ORG>
Date: Wed, 9 Sep 1998 15:29:49 -0400

Several issues have been brought up on PDF vs SGML. It should be mentioned
that PDF is as open as PostScript, and more portable (the language
is fully documented in published books, and a variety of free-ware and
commercial software can create or manipulate it). PDF also includes some
limited markup capabilities. And PDF documents are editable (Adobe's Acrobat
Exchange does this, for example). As far as information conveyance,
it's also important to note that no machine can understand content as
well as a human being, and humans prefer nicely formatted to marked-up
text - so PDF has an important purpose in helping preserve the formatting
of documents in an efficient manner (a few percent or less of the size
a comparable bitmap would take).

But we also need machine-comprehensible versions of texts, in order to
populate databases, provide search capabilities, and the like, and SGML
is probably ideal for that. The two formats (PDF and SGML) fill different
needs (human and machine readable texts) and their successors in future
will likely have at least these two functions to perform. In some cases
the human-readable version will be the authoritative one, and the machine-readable
one derived from it (by human-supervised OCR etc), in some cases it
will be the other way around, and in some cases both will be considered
authoritative for their distinct purposes. But it's not a matter of
one being preferable to another - both are essential now and for the
foreseeable future.

  Arthur (apsmith_at_aps.org)
Received on Tue Aug 25 1998 - 19:17:43 BST