the Platform for Intelligent Hypertext

PLINTH is an expertext shell. It integrates the technologies of hypertext, semantic nets and rule-based expert systems to provide tools and intelligent support for the authors and readers of technical documents.

PLINTH screen-shot

Here are some HTML versions of papers about the PLINTH system, along with the originals in gzip'd PostScript format:
Externally published papers on PLINTH: General papers on knowledge-based hypertext:
AIAI Andrew Casson-du Mont (