Twitter Emoji for Everyone by Twitter is licensed under CC-BY 4.0

Adwaita and Oxygen icons by GNOME and KDE Projects respectively are licensed under the GNU LGPL, version 3

Git Logo by Jason Long is licensed under CC-BY 3.0 (cropped, added white background)

Solarized color palette by Ethan Schoonover

zlib by Jean-loup Gailly and Mark Adler

Tango base icons are in the public domain