The code for http://jsno.de./flot/

app.js

var express = require('express'),
    app = module.exports = express.createServer();

app
    // Configuration
    .configure(function () {
        app.set('views', __dirname + '/views');
        app.set('view engine', 'jade');
        app.use(express.bodyDecoder());
        app.use(express.methodOverride());
        app.use(app.router);
        app.use(express.staticProvider(__dirname + '/public'));
        preloadFlot();
    })
    .configure('development', function () {
        app.use(express.errorHandler({ dumpExceptions: true, showStack: true })); 
    })
    .configure('production', function () {
        app.use(express.errorHandler()); 
    })
    // Routes
    .get('/', renderHomePage)
    .get('/flot', renderFlotImage)
;

// Only listen on $ node app.js
if (!module.parent) {
    app.listen(12914);
    console.log("Express server listening on port %d", app.address().port)
}

/* FIXME */
function preloadFlot()
{
    var document = require("jsdom").jsdom(),
        window = document.createWindow(),
        flot_location = 'http://jsno.de/javascripts/jquery.flot.svn.js',
        text_location = 'http://jsno.de/javascripts/jquery.flot.text.js',
        loadScript = function ( location, callback )
        {
            var script = document.createElement("script");

            script.src = location;
            if (callback) script.onload = callback;
            document.head.appendChild(script);

            return script;
        };

    window.Canvas = require('canvas');
    global.jQuery = require('jquery').create(window),
    loadScript(flot_location, function () { loadScript(text_location); });
}
/* eo FIXME*/

function renderHomePage( req, res )
{
    res.render('index', {
        locals: {
            title: 'JSNo.de'
        }
    });
}

function renderFlotImage( req, res )
{
    var params = require('url').parse(req.url, true),
        examples = [
            {data: example1Data(), options: example1Options() },
            {data: example2Data(), options: example2Options() },
            {data: example3Data(), options: example3Options() }               
        ],
        index = /*params.query.example % (examples.length-1) || */ random(0, examples.length-1),
        example = examples[index],
        placeholder = jQuery(''), // empty jQuery object
        plot = jQuery.plot(placeholder, example.data, example.options),
        node_canvas = plot.getCanvas(),
        node_canvas_plus_datestamp = datestampCanvas( node_canvas ),
        image = node_canvas_plus_datestamp.toBuffer();

    res.writeHead(200, {'Content-Type': 'image/png'});
    res.write(image, 'binary');

    function extend( obj, extObj ) 
    {
        if (arguments.length > 2) {
            for (var a = 1; a < arguments.length; a++) extend(obj, arguments[a]);
        } else {
            for (var i in extObj) obj[i] = extObj[i];
        }

        return obj;
    };

    function random( min, max )
    {
        min = min || 0;
        max = max || 1;

        var secs = (new Date()).getTime();
        var rand = min + Math.round( Math.random( secs ) * (max - min) );

        return rand;
    }

    function example1Data()
    {
        var i, d1 = [], d2 = [], d3 = [];
        for (i = 10; --i;) d1.push([i, parseInt(Math.random() * 30)]);
        for (i = 10; --i;) d2.push([i, parseInt(Math.random() * 30)]);
        for (i = 10; --i;) d3.push([i, parseInt(Math.random() * 30)]);

        return [
            {label: "one", data: d1, lines: { show: false, fill: true, steps: false }, bars: { show: true, barWidth: 0.6 } },
            {label: "two", data: d2, lines: { show: false, fill: true, steps: false }, bars: { show: true, barWidth: 0.6 } },
            {label: "three", data: d3, lines: { show: false, fill: true, steps: false }, bars: { show: true, barWidth: 0.6 } }
        ];
    }
    
    function example1Options()
    {
        return {
            width: 600, height: 300, 
            xaxis: { labelWidth: 50, labelHeight: 20 },
            yaxis: { labelWidth: 50, labelHeight: 20 },
            grid: {
                backgroundColor: "#eee",
                canvasText: {show: true, font: "sans 9px"},
                clickable: false, hoverable: false
            } 
        };
    }

    function example2Data()
    {
        var d1 = [], d3 = [], d4 = [], d5 = [], d6 = [];
        var d2 = [[0, 3], [4, 8], [8, 5], [9, 13]];
        var i, l = 14;
        for (i = 0; i < l; i += 0.5) d1.push([i, Math.sin( random(i, l) )]);
        for (i = 0; i < l; i += 0.5) d3.push([i, Math.cos( random(i, l) )]);
        for (i = 0; i < l; i += 0.1) d4.push([i, Math.sqrt( random(i, i * 10) )]);
        for (i = 0; i < l; i += 0.5) d5.push([i, Math.sqrt( random(i, l) )]);
        for (i = 0; i < l; i += 0.5 + Math.random()) d6.push([i, Math.sqrt(2*i + Math.sin(i) + 5)]);
        
        return [
            { data: d1, label: "one", lines: { show: true, fill: true } },
            { data: d2, label: "two", bars: { show: true } },
            { data: d3, label: "three", points: { show: true } },
            { data: d4, label: "four", lines: { show: true } },
            { data: d5, label: "five", lines: { show: true }, points: { show: true } },
            { data: d6, label: "six", lines: { show: true, steps: true } }
        ];
    }

    function example2Options()
    {
        return {
            width: 600, height: 300,
            xaxis: { labelWidth: 50, labelHeight: 20 },
            yaxis: { labelWidth: 50, labelHeight: 20 },
            grid: {
                backgroundColor: "#eee",   
                canvasText: {show: true, font: "sans 9px"},
                legend: {
                    position: "sw",
                    backgroundColor: "#de4",
                    backgroundOpacity: 0.35
                }
            }
        };
    }

    function example3Data()
    {
        var i, PI2 = Math.PI*2, d1 = [], d2 = [], d3 = [];
        for (i = 0; i < PI2; i += 0.25) d1.push([i, Math.sin(i)]);
        for (i = 0; i < PI2; i += 0.25) d2.push([i, Math.cos(i)]);
        for (i = 0; i < PI2; i += 0.1) d3.push([i, Math.tan(i)]);
        
        return [
            { label: "sin(x)",  data: d1 },
            { label: "cos(x)",  data: d2 },
            { label: "tan(x)",  data: d3 }
        ];
    }

    function example3Options()
    {
        return {
            width: 600, height: 300,
            series: { lines: { show: true }, points: { show: true } },
            xaxis: {
                labelWidth: 50, labelHeight: 20,
                ticks: [
                    0, 
                    [Math.PI/2, "Pi/2"], 
                    [Math.PI, "Pi"], 
                    [Math.PI * 3/2, "3*Pi/2"], 
                    [Math.PI * 2, "2*Pi"]
                ]
            },
            yaxis: { 
                ticks: 10, min: -2, max: 2,
                labelWidth: 50, labelHeight: 20 
            },
            grid: { 
                backgroundColor: "#eee",
                canvasText: {show: true, font: "sans 9px"}
            }
        };
    }

}

function datestampCanvas(canvas)
{
    var ctx = canvas.getContext('2d');
    var date = new Date();
    var utc_string = date.toUTCString();

    ctx.globalAlpha = 1;
    ctx.font = "bold 30px sans-serif";

    ctx.translate(20, -40);

    ctx.lineWidth = 1;
    ctx.strokeStyle = '#aaa';
    ctx.strokeText(utc_string, 50, 100);
    ctx.strokeText(date.getTime()+' epoch ms', 100, 150)

    return canvas;
}