PROBABLY WON'T FIX:
Embedded rules language not updated when language is set (in Analyse, Game and Problems)
If new live game starts in background, "new game" notify OK but not first move.

NEW VARIANTS:
https://www.chessvariants.com/mvopponent.dir/hypnotic-chess.html
https://www.chessvariants.com/mvopponent.dir/mesmer-chess.html
https://www.reddit.com/r/TotemChess/comments/imi3v7/totem_rules/
--> replaced by "Joker" chess --> start on bishop of our color (instead),
    moves like a Bishop + Dabbabah, can swap with a piece *on same color* (as a move) at anytime. hmm
    or rather: start as in Antiking + Mesmer, in front of. moves like an amazon. swap with any color. better!
http://history.chess.free.fr/rollerball.htm
  https://www.chessvariants.com/40.dir/rollerball/index.html

https://www.pychess.org/variant/shogun
https://www.chessvariants.com/other.dir/fugue.html
https://www.chessvariants.com/rules/spartan-chess
https://www.chessvariants.com/incinf.dir/bario.html
  https://www.chessvariants.com/index/listcomments.php?order=DESC&itemid=Bario
  https://www.bario-chess-checkers-chessphotography-spaceart.de/
  https://le-cdn.website-editor.net/20ef5f800ea646c29f6852cfc5ceda07/dms3rep/multi/opt/BAR028-e15a849c-960w.jpg

https://musketeerchess.net/games/musketeer/index.php Attention règle de promotion + SVG / PNG
https://musketeerchess.net/games/cerebral/rules/rules.php : from Titan, should be easy

Non-chess:
gomoku, avalam, draughts, draughts8
Yoté https://fr.wikipedia.org/wiki/Yot%C3%A9 http://www.zillionsofgames.com/cgi-bin/zilligames/submissions.cgi/92187?do=show;id=960
Fanorona https://fr.wikipedia.org/wiki/Fanorona

(puis quand hexaboards peut-être: hexavariants + Hex)
qoridor (wider lines in another color ?)