Hello

	There is a free code developed by a student at our site, it is
in ftp.iqm.unicamp.br/pub/chemistry/molecular_surface/surf, there you'll
find:
	surf-ps.doc.z   the paper published in Computers & Chemistry in
			Postscript format
	surf.doc.z      The same paper but (I'm not sure) in troff format
        surf.f.z        the program itself 

the .z sufix means it was compressed using GNU gzip

Regards

Pedro