At the time, PAT was claimed as the only native SGML database product incollection. It was created to provide indexing search for the Oxford Dictionaries project at the University of Waterloo, and later commercialised by OpenText Corporation. PAT was available for SunOS 4.1.3 (this author’s platform in those days) and was installed for the CELT project for searching their TEI corpus of Irish writing. It continued in use until the platform failed in a lightning strike in 2003 (resuscitation is currently ongoing, as this was the world’s ninth web server).

PAT’s main advantages were the ease of ingestion of a new corpus (basically a single vast, monolithic SGML document), and the speed of a search. Significant scripting was needed at CELT to turn the KWIC format output into a fully-referenced page for the web, as it meant revisiting each hit to look up the element types needed to compose a reference, and then again to retrieve the reference points themselves, resulting in a slower-than-optimal return, but acceptable in those days.