This is Debian GNU/Linux's prepackaged version of the NASA's CLIPS
expert system.

This package was put together by me, Javier Fernandez-Sanguino Peņa
<jfs@computer.org>, from the NASA sources, which I obtained from
http://www.ghgcorp.com/clips/download/source/ and 
http://www.ghgcorp.com/clips/executables/examples

CLIPS is, as stated in its FAQ (www.ghgcorp.com/clips/CLIPS-FAQ) freely
distributable:

"
(...)

 4) CAN CLIPS BE REDISTRIBUTED? ARE THERE ANY LICENSING FEES?
-------------------------------------------------------------
  Copies of CLIPS executables, documentation, and source code
  downloaded from http://www.ghg.net/clips/download/ can be
  freely used, modified and redistributed without restrictions.

(...)

"