"Where do I think it will be?" Hmm. Well, I certainly didn't invent the concept of a rule engine; it's been around for a long time, and in fact, Jess doesn't own the market. Jess's big-name competitors include ILOG JRules, Blaze Advisor, and BEA WebLogic. Jess's particular niche within this industry is that it's the rule engine for "Real Programmers" -- people who want the extra control and flexibility that you get from having full source code and real technical support, and people who want the ability to use the same engine in a range of products, from embedded controllers to desktops to enterprise servers (sorry, I'm sounding like an advertisement, here.)
Anyway, a lot of large-scale projects
are using rule engines. Jess's customer list includes a few dozen Fortune 500 companies, and rule-based software is approaching a billion-dollar industry.
Jess in Action does indeed contain sample applications: four in all, with 2 to 3 chapters spent developing each. None of them are toys. The big motivation to write this book was that there simply weren't any tutorial examples on using rule engines in the literature; now there are!
Now, finally: Waiting for what book to come out? Jess in Action and Manning's "AspectJ in Action" are both available right now from Amazon (see link below.) Get yours today!
