Chess piece artwork by Cburnett, with Wikimedia contributor adjustments.
Unmodified SVG artwork, distributed under Creative Commons Attribution-ShareAlike 3.0.
https://creativecommons.org/licenses/by-sa/3.0/
Originals: https://commons.wikimedia.org/wiki/Template:SVG_chess_pieces
Mirror: https://github.com/lichess-org/lila/tree/master/public/piece/cburnett
Files are renamed to identify piece colour and type. The surrounding application is not part of the artwork.