PGOPHER is a general purpose program for simulating and fitting rotational, vibrational and electronic spectra. Included here are executables, source code, documentation and sample files for version 9.1.100 of the PGOPHER program. This is an update for version 8.0.102, also available in this repository Please also see the program web site, http://pgopher.chm.bris.ac.uk/. The program is open source, and covered by the LGPL. The documentation and other files are covered by the University of Bristol repository's Non-Commercial Government License, except where explicitly noted.