Dan Helfman <witten@torsion.org>: Main developer

Alexander Görtz: Python 3 compatibility
Florian Lindner: Logging rewrite
Henning Schroeder: Copy editing
Johannes Feichtner: Support for user hooks
Michele Lazzeri: Custom archive names
Nick Whyte: Support prefix filtering for archive consistency checks
newtonne: Read encryption password from external file
Robin `ypid` Schneider: Support additional options of Borg and add validate-borgmatic-config command
Scott Squires: Custom archive names
Thomas LÉVEIL: Support for a keep_minutely prune option. Support for the --json option

And many others! See the output of "git log".
