Lichess Forks and Lichess based sites:https://www.pychess.org Different variants (a lot of them)https://lichess.dev Lichess Developer Instance (it requires a login)https://mskchess.ru Russian Lichess (hosted in Russia, Moscow)https://arena.chess-land.com/ similar to lichess v.1https://playstrategy.org/ Lichess fork (hosted in the UK) with new variantshttps://live.chess-online.com Lichess fork (hosted in the Netherlands)https://chess-academy.net/ Old version of lichess (hosted in Germany)https://haichess.com/ Chineese website based on Lichess (hosted in China)https://liantichess.org/ Antichesshttps://liantichess.herokuapp.com/ Antichess websitehttps://www.schach-spielen.eu German speaking chess site (similar to Lichess)https://www.chessonlinefree.com/ a bit similar to Lichesshttps://en.chessrook.com/ International Company online arena (similar)www.chessroots.com/ Opening explorerhttps://chessboardbattle.com/ Play against the computerhttp://chesstacticsgenerator.vitomd.com/ Generating tacticshttps://playgrandmasters.com/ Replay the grandmasters against the computerhttps://www.freechess.club/ Open source sitewww.kfchess.com/ Interesting new chess varianthttps://lichess.thijs.com/rankings/all/all/list_players_trophies.html Statshttps://rosen-score.vercel.app/ How many Rosen trophies do you have?https://www.holygambitgrail.com/ How many gambits have you won with?https://freopen.org/ World chess champion numberhttps://listudy.org/ lichess studyshttp://eloguessr.com/ guess the elohttps://jackli.gg/chessle/ guess the openinghttps://chessvariants.training/ Chess variants trainingwww.openingtree.com/ Download openings
Puzzles and Puzzle Rush free:https://blitztactics.com Different puzzles based on Lichesshttps://chesscup.org Free Puzzle Rushhttps://listudy.org Studies, tactics, endgames
Blindfold trainers:http://noirchess.azurewebsites.net/blindfoldtrainer/ Blindfold trainerhttps://en.chessfish.com/content/chess-blindfold-trainer/ Blindfold trainerhttps://chessinsights.org/ Blindfold trainer
https://online-go.com/observe-games Go
https://play.xiangqi.com/ Chinese Chess
https://lishogi.org/ Looks like lichess, just with the game Shogi
https://lidraughts.org Checkers and variants of checkers
https://lichess.org/@/Krukulu others contributing with links, and many links are open-source sites https://lichess.org/blog/X8fGPxUAAHY74FSO/our-favorite-open-source-sites-2 and https://lichess.org/blog/WrbfjyYAAMOualZ5/our-favourite-open-source-chess-websites
Source: https://lichess.org/team/lichess-based-websites-and-links
