The ghostscript interpreter may be obtained via anonymous ftp from ftp.cs.wisc.edu.
gv is based on Tim Theisen's ghostview 1.5. ghostview 1.5 may be obtained via anonymous ftp from ftp.cs.wisc.edu.
The sources of Kaleb S. Keithley's modification of the Xaw widget set may be obtained via anonymous ftp from ftp.x.org.