Betafish.js is a chess AI designed for web-based applications. It is written in JavaScript and operates in the browser, allowing users to play against a chess AI without the need for any additional hardware or software.. The AI utilizes the FEN (Forsyth-Edwards Notation) standard to keep track of the game state and make moves accordingly. Betafish.js also comes with a customizable chessboard component built with CSS and HTML, as well as a set of staunty pieces and markers sprites.. The AI can be configured to think for a certain amount of time and users can take back any move they make. The source code for Betafish.js is available on Github, and the AI was developed by Gavin..