Snip!t from collection of Alan Dix

<b><i>Jess</i></b> is a rule engine and scripting environment written entirely in Sun's <a href="http://java.sun.com" target="_top">Java</a> language by Ernest Friedman-Hill at <a href="http://www.sandia.gov" target="_top">Sandia National Laboratories</a> in Livermore, CA. Using <b><i>Jess</i></b>, you can build Java software that has the capacity to "reason" using knowledge you supply in the form of declarative rules. <b><i>Jess</i></b> is small, light, and one of the fastest rule engines available. Its powerful scripting language gives you access to all of Java's APIs. <b><i>Jess</i></b> includes a full-featured development environment based on the award-winning Eclipse platform.