cm-chessboard

Example: Responsive chessboard with an aspect ratio of 0.9

new Chessboard(document.getElementById("board"), {
        position: FEN.start,
        assetsUrl: "../assets/",
        style: {
            aspectRatio: 0.9,
            pieces: {file: "pieces/staunty.svg"},
            borderType: BORDER_TYPE.frame
        },
        extensions: [{class: AutoBorderNone}]
    })

This example also uses the "AutoBorderNone" extension, which switches off the frame border on smaller boards.