If you've been keeping your ear to the ground, you may have heard some talk recently about "rules", "business rules" and "rules engines", but not necessarily any clear discussion on what they are, how to use or design them, or why they might be useful or important.

This presentation puts some concrete definition around what a "rule" is, how a "rule engine" like JESS (Java Expert System Shell) can enable your users to be more agile than they ever thought possible, where JSR-94 fits into both the J2EE and "lightweight" development environments, and how you can (finallY!) get out of the "infinite if-else game".