Lucas Chess, (LucasChess)
a free, UCI compliant cross platform chess GUI by Lucas Monge and contributors , written in Python, released as open source under the GPL 3.0. Lucas Chess (R), released in June 2020, requires Python 3.7 rather than 2.7 and PySide2 (Qt5) instead of PyQt4 as the main graphic library, and further uses python-chess by Niklas Fiekas .
Lucas Chess - Move Tree 
Beside game playing and analysing with UCI engines in various modes and training sessions, Lucas Chess features game and position database functions, is able to load and save games in Portable Game Notation (PGN) and to copy and paste Forsyth-Edwards Notation (FEN) from the clipboard. It further features strength adjustment and determination, use and creation of PolyGlot opening books with ECO classification, and various e-boards . Finally, Lucas Chess is able to play tournaments between engines.
- Lucaschess: a program with increasing level of difficulty by E Diaz, CCC, July 14, 2011
- Lucas Chess 6.0 by lukasmonk, CCC, October 07, 2011
- desperate HELP needed for a chess gui by Michele Tumbarello, CCC, September 15, 2012
- Lucas Chess GUI v10.10 by Norbert Raimund Leisner, CCC, December 27, 2016
- Lucas Chess new version 11 by lukasmonk, CCC, November 01, 2017
- LucasChess 11.04a by reflectionofpower, CCC, January 09, 2018
- Lucas Chess R 1.23 by Roland Chastain, CCC, June 06, 2021
- New DGT driver and updated eBoard drivers (Windows/Linux) by Graham O'Neill, CCC, July 23, 2021 » DGT Board
- Lucas Chess
- Lucas Chess Fresh News
- GitHub - lukasmonk/lucaschessR: Chess GUI (Python 3.7)
- GitHub - lukasmonk/lucaschess: Chess GUI