Is there any problem mentioning other chess sites?

@Toadofsky Wow, that's a fun variant! I'ts going to take a while for me to beat the level 1 AI...

I'm just naming the most obvious for now:

www.chesstempo.com
www.chessbomb.com
www.chessbase.com
www.chessgames.com

Every one of these has it's unique qualities, I never saw them as "competitors"

@Toadofsky this varient hurts my brain :P

@Toadofsky that is a great re-experience how i looked at the board when i was a beginner ... I need to stop dropping my queen :-)

The background music also fits well.

#14 Indeed, thanks to NM John "ZugAddict" Chernoff for his musical contributions to Relay Chess! :-)

@ZugAddict, which music software do you use?

@others
Here some more interesting chess sites:

Tim Krabbé's Chess Curiosities – timkr.home.xs4all.nl/chess/
Chess Notes By Edward Winter – http://www.chesshistory.com/winter/archives.html
Yet Another Chess Problem Database – www.yacpdb.org/#static/home

Here some database links providing food for your chess game collection. Which you may manage using Scid – http://scid.sourceforge.net/.

15 million games in misc databases – sourceforge.net/projects/codekiddy-chess/files/
Gorgonians game collection – http://gorgonian.weebly.com/pgn.html
Kings Base by Pierre Havard – http://www.kingbase-chess.net/
Misc gam Collections scraped by someone from chessgames.com – http://smallchess.com/Games/
TWIC latest games downloads[1] – theweekinchess.com/twic

Not chess related, but maybe just chess is sometimes not interesting enough for you people:

The Go equivalent to lichess – online-go.com/

Trackmania Nations Forever, the greatest race game ever, once you figured out how to slide you will know what i mean – free! (You rock, Florent) – Trailer: www.youtube.com/watch?v=zwhC0PCYAa4 – Download: http://trackmaniaforever.com/nations/ – Download tracks and world records: tmnforever.tm-exchange.com/

@Toadofsky Finally I managed to beat the level one in relaychess. It was easy to capture the queen, because the engine always plays the same moves (e4 d5 exd5 Qxd5 Cc3 Qd6 Bb5+ and them Bxd6 next) but still it was very difficult to win... I just won by exchange all the pieces and then playing a normal endgame.

@Klartext I think for that I actually just used Finale which is a notation program that ships with a bunch of orchestral samples and playback features.

I nominate www.kfchess.com/ as the best chess variant ever created.

@redban I soundly agree 😝😝😝😝😝