There si no licence-problem with porting r.fuzzy to GRASS 5.x:
From: DELCLAUX Francois <francois.delclaux@msem.univ-montp2.fr>
Subject: Re: r.fuzzy
Date: Tue, 02 Nov 2004 20:13:53 +0000
To: Jachym Cepicky <jachym.cepicky@centrum.cz>
There is no licence concerning the r.fuzzy programs. I would be happy if
somme one is volunteer for doing this job.
Francois Delclaux
----- End forwarded message -----
So I would by happy too, if someone would do this job 
Jachym
--
Jachym Cepicky
e-mail: jachym.cepicky@centrum.cz
URL: http://les-ejk.cz