SNePS is the Semantic Network Processing System.  It is the
implementation of a fully intensional theory of propositional
knowledge representation and reasoning.  

SNePS is available via anonymous FTP from ftp.cs.buffalo.edu
[128.205.32.53], in directory /pub/sneps/.

SNePS 2.5.1 is available under the GNU GPL.  Other versions
may be available under non-free licenses.

- FSF Staff