The ghostscript interpreter may be obtained via anonymous ftp from mirror.cs.wisc.edu.
gv is based on Tim Theisen's ghostview 1.5. ghostview 1.5 may be obtained via anonymous ftp from mirror.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.