A (not written in Common Lisp) Knowledge Representation & Reasoning System. PowerLoom is implemented in 
stella that can be translated into 
Lisp, C++ and 
Java and therefore available in Common-Lisp version. It is a successor to 
LOOM. As Wikipedia article claims, LOOM could be used as a deductive layer that overlays an ordinary 
CLOS network so that users can obtain many of the benefits of using Loom without impacting the function or performance of their CLOS-based 
applications. See 
Retrospective of Loom and references therein for details.
[PDF] PowerLoom manual
Homepage: at isi.edu
License: MPL, GPL, LGPL (see PowerLoom Downloads page for details).
See Also: KR
Topics: 
Knowledge Representation Systems