HTML5 2d starfield example.html

<!DOCTYPE=html>
<html><body>
<canvas id="myCanvas" width="320" height="240" style="border:1px solid #d3d3d3;">
Use different browser.
</canvas>
<script>
    var c=document.getElementById("myCanvas");
    var ctx=c.getContext("2d");
    var sx = new Array(100);
    var sy = new Array(100);
    var ss = new Array(100);
    
    for(i=0;i<sx.length;i++){
        sx[i]=Math.round(Math.random()*c.width);
        sy[i]=Math.round(Math.random()*c.height);
        ss[i]=Math.round(Math.random()*3+1);
    }
    
    gameloop=setInterval(doGameLoop,16);
    function doGameLoop(){
        ctx.fillStyle="black";
        ctx.fillRect(0,0,c.width,c.height);
        // Draw the stars.
        ctx.fillStyle="white";
        for(i=0;i<sx.length;i++){
            ctx.fillRect(sx[i],sy[i],2,2);
        }
        // Update the stars position.
        for(i=0;i<sx.length;i++){
            sx[i]-=ss[i];
            if(sx[i]<0) sx[i]=c.width;
        }
    }
    
</script></body></html>