Teaching differential equations with Maxima



 From the file "readme.now"..
ftp://ftp.mines.colorado.edu/pub/papers/math_cs_dept/software/readme.now

You are welcome to use any of the software packages free of charge 
for scientific work, with acknowledgement of the developers and proper 
reference to either our research papers or to the software, or to both.

The software may not be reproduced or sold without written consent 
of the authors (Copyright 1995-2002).

...........

So don't sell it, and don't use it for UNscientific work.  It is pretty 
clear that it
is not owned by Macsyma Inc.  My guess is that you could pretty much
indefinitely expect the software to be available on the internet, even 
if you
didn't make a local copy. But you might email the authors to see if it
could be put into sourceforge.
RJF