We use a variety of open source software, under several licenses:

• DotNetZip (Microsoft Public License)
• Diffplex (minor modifications to run on .Net 2.0, Microsoft Public License since changed to Apache 2.0)
• Sharp Vector Graphics (significantly improved, contact us if interested, Modified BSD License)
• Mono.Data.Sqlite (MIT License)
• Mono.Options (MIT License)
• Learn Them uses Vorbis# (csvorbis) copyright (C) 2000 ymnk, JCraft,Inc (Modified version with OggDecodeStream extracted as DLL, LGPL V2)
• Spell It uses NHunspell and therefore Hunspell (MPL V1.1)

On non-Windows platforms, the PAR software is run via Mono. We have made significant improvements / fixes to mono, particularly System.Windows.Forms, and a small change to mono-basic. Mono is a separate program, and it combined with its dependencies are distributed in binary form under the GPL Version 3 with source code available below under each libraries' own license. Mono itself is MIT Licensed. On these platforms Mono is installed in the "mono" subdirectory of the application directory. The licenses for Mono and its dependencies can be found in the "share/doc/licenses" subdirectory of that, or in the source code. Mono (libgdiplus in particular) is based in part on the work of the Independent JPEG Group.

• Source code for Mono. See below for configuration details. MIT licenced.
• Source code for Mono dependencies. We distribute these dependencies in Mac installs, and have the source code available here to meet license requirements. None of these are modified from upstream, but one needs to be configured correctly on Mac (see below for configuration details). On Linux these are probably pre-installed, and no special configuration would be needed. Each library is licenced under its respective licence, as indicated in the relevant directory in the archive.
• Configuration details for macOS.