You may also be interested in the Postscript downloading FAQ of the xxx.lanl.gov e-Print archive.
Windows users may be interested in a description of installing a Postscript (and a PDF) viewer.
MacOS users may want to try MacGhostView which works better on one of my files than the MacGS version of Ghostscript.
Postscript can also be converted to plain text, HTML, and other formats; the PreScript page contains such a converter and links to other converters.
For the other direction, here are guides on how to create PostScript files on Windows and MacOS.