[ishi]

Back in 2003 I worked for a startup that used CLIPS. While it's quite powerful and expressive, as the number of rules grows it becomes very difficult to reason about and debug them. The application logic becomes spaghetti-like and very brittle. So it's an interesting paradigm to learn about, but not very useful for real-world applications IMO.

[JabavuAdams]

Sounds like game logic. There was a board-game prototype a friend was working on, and I suggested using a rules-based approach for coding the game logic.

More recently, I was tempted to make a tool for the designers on Storm Casters to specify game and meta-game logic like this, but had to abandon that due to higher priorities.