Qi
Qi is a new functional programming language designed to run under Common Lisp. Qi provides type security and extra clarity to your Lisp application programs without heavy cost to portability or performance. It is particularly suited to the development of distributed reasoning programs or intelligent agents. The latest release, Qi 6.1, runs under CLisp. It is available under the GPL licence [GPL]. Here are some of the features of Qi.
  • Implemented in Common Lisp
  • Inbuilt programmable inferencing engine
  • Backtracking available
  • Easy access to Common Lisp
  • lambda calculus consistent
  • Inbuilt Prolog engine.
  • Inbuilt compiler-compiler.
  • Online documentation.
  • Optional static type checking
  • Pattern matching
  • Formal semantics provided
  • Correctness proofs

Homepage: http://www.lambdassociates.org