(C) 2021, Yoxem Chen (aka Tan Kian-thing). Under GPL v3.

The pdf.js part (in thirdparty/) is under Apache License 2.0<https://github.com/mozilla/pdf.js/blob/master/LICENSE>, a
uthor is listed here: https://github.com/mozilla/pdf.js/blob/master/AUTHORS

The icons is based on the work from Tango Project (http://tango.freedesktop.org,
download link: http://tango.freedesktop.org/releases/tango-icon-theme-0.8.90.tar.gz under Public Domain.
staff: http://tango.freedesktop.org/The_People). Part of the icons are modified by Yoxem Chen.