Yoann Le Montagner
Marek Śmigielski, Paul Schreiber, Adam Silverstein, Paolo Fantozzi.
Jan Jílek (Czech), Markus Liebelt (German), Yoann Le Montagner (English and French), Martin Frith (Spanish), Atilla Szvetlik (Hungarian), Andrea Cuccarini (Italian), Ivan Deceuninck (Dutch), Dawid Ziółkowski (Polish), Rewbenio Frota (Brazilian Portuguese), Sergey Baravicov (Russian), Ali Nihat Yazıcı (Turkish).
Pieceset CBurnett has been created by Colin M.L. Burnett, who shares it under the [CC-BY-SA] license on Wikimedia Commons; user Antonsusi has also contributed to this work. Piecesets Celtic, Eyes, Fantasy, Skulls and Spatial have been created by Maurizio Monge, who makes them freely available for chess programs. Colorsets Coral, Dusk, Emerald, Marine, Sandcastle and Wheat have been proposed in this blog post by Gorgonian.
The author would like to thank all these people for their highly valuable work.