Wow this brings back memories. I studied this language in europe back when I was a kid (must have been around 20 years ago). Very interesting and it definitely changes the way one thinks about programming. Too bad the purpose it was written for (the so called expert systems) never really became popular.
> Too bad the purpose it was written for (the so called expert systems) never really became popular
My impression is that expert systems became too popular (for a while, they were an overworked subject in CS academia and industrial hype literature alike) and died from an excess of broken promises.
For a current successful commercial expert system see for example http://www.zenprise.com -- Zenprise is a rule-based expert system that monitors Microsoft Exchange and Blackberry server deployments, and Active-Sync (Windows Mobile, iPhone, etc.) and Blackberry phones. It automatically monitors system configuration and real-time telemetry to find where problems are in a corporation's message system and help administrators avoid those 3 a.m. phone calls from irate CEOs who aren't getting their emails while working/traveling in Asia.
There are several thousand rules actively monitored and rule violations trigger alerts with resolution plans ... IT personnel can go through the resolution to further troubleshoot and fix their problems. It also identifies the underlying cause for a particular problem (root-cause analysis) ... when one link goes down there are many symptoms. The system's set up to identify the most likely common cause for all those systems. Pretty nice.
