Since the first days of SGML, there has been a variety of software to parse, validate, analyse, format, store,
search, and extract the information. Some of this was what we now call Open Source, particularly the
smaller utilities, but the majority of applications were conventional commercial offerings.
In the course of time, many of these have become unavailable, for assorted reasons, with the result is that
some very useful systems have been lost, and replacements are not always as effective.
This research attempts to catalogue and analyse a collection of XML and SGML software that is either
off the market, or only available within a different product, and thus not accessible to users. The
objective is to see if there are still ways to shorten the distance between the bricks that are not otherwise