The Lisa project is a platform for the development of Lisp-based Intelligent Software Agents.
Lisa is a production-rule system implemented in the Common Lisp Object System (CLOS), and is heavily influenced by CLIPS and the Java Expert System Shell (JESS).
At its core is a reasoning engine based on an object-oriented implementation of the Rete algorithm, a very efficient mechanism for solving the difficult many-to-many matching problem.
[1] Intrinsic to Lisa is the ability to reason over CLOS objects without imposing special class hierarchy requirements; thus it should be possible to easily augment existing CLOS applications with reasoning capabilities.
Lisa-enabled applications should run on any ANSI-compliant Common Lisp platform.