Lichess based websites and links

A team for useful websites and links connected to Lichess.
If you know any website (especially Lichess forks), you can send it here or in PM.

Lichess Forks and Lichess based sites:

https://lichess.org Lichess Official
https://lichess.dev Lichess Developer Instance (it requires a login and password now)
https://mskchess.ru Russian Lichess (hosted in Russia, Moscow)
https://arena.chess-land.com/ similar to lichess v.1
https://playstrategy.org/ Lichess fork (hosted in the UK) with new variants
https://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, probably Beijing)
https://lidraughts.org Checkers and variants of checkers
https://liantichess.org/ Antichess
https://liantichess.herokuapp.com/ Antichess website
https://www.pychess.org Different variants (a lot of them)
https://www.schach-spielen.eu German speaking chess site (a bit similar to Lichess)
https://www.chessonlinefree.com/ a bit similar to Lichess
https://en.chessrook.com/ International Company online arena (similar to Lichess)
https://lishogi.org/ looks like lichess, just with the game shogi
www.openingtree.com/ Download openings
www.chessroots.com/ Opening explorer
https://chessboardbattle.com/ Play against the computer
http://chesstacticsgenerator.vitomd.com/ Generating tactics
https://playgrandmasters.com/ Replay the grandmasters games against the computer
https://www.freechess.club/ Open source site
www.kfchess.com/ Interesting new chess variant
https://lichess.thijs.com/rankings/all/all/list_players_trophies.html Tournament stats
https://rosen-score.vercel.app/ How many Rosen trophies do you have?
https://freopen.org/ World chess champion number
https://listudy.org/ lichess studys
http://eloguessr.com/ guess the elo
https://jackli.gg/chessle/ guess the opening

Puzzles and Puzzle Rush free:
https://blitztactics.com Different puzzles based on Lichess
https://chesscup.org Free Puzzle Rush
https://listudy.org Studies, tactics, endgames

Blindfold trainers:
http://noirchess.azurewebsites.net/blindfoldtrainer/ Blindfold trainer
https://en.chessfish.com/content/chess-blindfold-trainer/ Blindfold trainer
https://chessinsights.org/ Blindfold trainer

https://online-go.com/observe-games Go

https://chessvariants.training/ Chess variants training

(Thanks to https://lichess.org/@/Krukulu and others for 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 ))