The Chess Variants Club

Choose the chess variant you’d like to play sorted by piece sets
… or sorted by board size

Play and discover 12 popular chess variants, improve your chess skills with hundreds of chess puzzles, or simply play regular chess with your friends – all in one package.

This diverse collection includes several chess games and puzzles that will entertain you and your friends for thousands of hours. All in a minimalist, beautifully designed virtual chess club.
Here is the list of Chess Variants currently available (more to come soon):

Demi-Chess;
Dunsany’s Chess;
Chess960 (Fischer Random Chess);
Los Alamos Chess;
Atomic Chess;
Silverman Chess;
Microchess;
Diana chess;
Circe Chess;
Dunsany’s Chess;
3-Checks Chess;
Knight Supreme Chess;
The Pawns Game;
Aleut Chess.

Key Features:
Play against the computer or with your friends (local multiplayer or Remote Play Together);
Originally composed soundtrack to help you relax and concentrate;
12 Chess Variants to learn and play (more to be added soon!);
More than 400 chess puzzles to solve (Classical Chess, Atomic Chess, 3-Checks Chess, Micro-Chess, Demi-Chess, Diana Chess, Circe Chess, and more to come soon);
Hundreds of chess puzzles available

Play a chess match remotely with a friend, with Remote Play Together.
Invite your friend to play with you. He/she doesn’t need to have a Steam account – see here;
The remote player can use the shared mouse, the shared keyboard, or a gamepad (it currently works for a limited set of controller models).
The input devices to be shared are defined by the player who made the invitation and is running the game;
The definition of which input device will be used by which player is made at the start of each match.

Source: TheGamesDB