HTML
<canvas id="canvas" width=300 height=100 style="background-color:#808080;">
</canvas>
Javascript
var canvas = document.getElementById("canvas");
var ctx = canvas.getContext("2d");
ctx.font = "34px serif";
ctx.textAlign = "center";
ctx.textBaseline="middle";
ctx.fillStyle = "#FFF";
ctx.fillText("Hello World",150,50);
Result