SGML: Announcing LT NSL: A simple SGML application development toolkit

SGML: Announcing LT NSL: A simple SGML application development toolkit

From Fri May 24 08:11:57 1996
Message-Id: <>
From: "Henry S. Thompson" <>
Date: Fri, 24 May 96 12:15:45 BST
Subject: Announcing LT NSL: A simple SGML application development toolkit


The HCRC Language Technology Group, University of Edinburgh, is
pleased to announce the public release of LT NSL.

LT NSL is a UNIX-based development environment for SGML-based corpus
and document processing, with support for multiple versions and
multiple levels of annotation.  It consists of a C language API for
accessing and manipulating SGML documents and an integrated set of
SGML tools, including a powerful grep-style utility.

The LT NSL initial parsing module incorporates v1.0 of James Clark's
SP software, arguably the best SGML parser available.  The basic
architecture is one in which an arbitrary SGML document is parsed
once, yielding two results:

 1) An optimised representation of the information contained in the
    document's DTD;

 2) A normalised version of the document instance, which can be piped
    through any tools built using our API for augmentation, extraction,

The use of the cached DTD together with the normalisation of the
SGML to nSGML means that applications processing nSGML streams can be
very efficient.

LT NSL provides two views of an nSGML file; one as a flat stream of
markup tags and text; secondly as a sequence of tree-structured
SGML elements. The two views can be mixed, allowing great flexibility
in the manipulation of SGML documents.  It also includes a powerful,
yet simple, querying language, which allows the user to quickly and
easily select those parts of an SGML edocument which are of interest.
Finally, LT NSL supports SGML output, making it easier to write SGML
to SGML conversion programs.

In beta testing, LT NSL has demonstrated that it supports rapid
prototyping of efficient SGML applications.  Its provision of a
pipelined architecture enables complex applications to be developed in
a modular fashion which facilitates re-use and specialisation.

An interface to the Python language has also been developed, allowing
the quick development of graphical user interfaces using the NSL API.

For access to introductory papers about LT NSL, the software and user
 manual, see
 [ or possibly ?, rcc]