Play games online at FICS, or play the Pulsar Engine with Chess and Variants like Crazyhouse, Losers and Atomic with 8 levels, and use the Opening Explorer. If no account connect as guest for unrated casual play. FICS is non profit, and there is a sign up link for a free lifetime account when logged in as a guest in console as a resource. Diamond is free and ad free.
The Chess Openings Explorer on tab three has an opening book built from 345,000 over the board games were both players are rated at least 2300. Users can flip between the book and Stockfish Engine Analysis. There are 11 PGN classic game collections as well as the users log file that can be loaded in this view. They include Fischer's Memorable games, Morphy 1958, Kasparov and Capablanca collections and a range of collections from classical to modern. This works offline as well.
Diamond has Stockfish engine analysis while examining or observing such as when choosing examine last game on Board Actions menu. There is a seek a game view on the Board's Options menu to find games as well as a Seek graph where seeks are posted. The Seek Graph can let users play up by finding higher rated players seeking if they want.
Watch high rated online chess games going on with the Watch Game option on board. Guests can use this option.
Members can chat in channels with other chess players online. Politics (39) and shouts are most active, and there are some others as well. Tap channels button in lower right of console to enter a channel.
There are a variety of settings and pieces and chess boards can be customized. Diamond also support most all server variants including Crazyhouse, Loser’s, Chess960(known as wild fr on FICS) and Atomic and guests can play any of these too.
Users played games are logged in PGN format and there is an option on the board to open the log file to upload games to an examine board or export out the file as a mail attachment. Must be connected as guest or member to view PGN as it uses the server's examine mode. Offline the Explorer tab can be used to load these games.
Diamond has the chess server's lag compensation software, timeseal on FICS, the Free Internet Chess Club.