Known contributors are listed here, in alphabetical order by their
abbreviations (which are used in Changelog).

Main author:

 PS1 Peter Selinger <selinger at users.sourceforge.net>

Contributors:

 CH1 Christoph Hormann <chris_hormann at gmx.de> (GeoJSON backend)
 TA1 Tor Andersson <tor at ghostscript.com> (PDF backend)