node-highcharts.js

var jsdom = require('jsdom'),
        spawn   = require('child_process').spawn;

function createHighchartsWindow(callback) {
        var window      = jsdom.jsdom().createWindow(),
                script  = window.document.createElement('script');

        // Convince Highcharts that our window supports SVG's
        window.SVGAngle = true;

        // jsdom doesn't yet support createElementNS, so just fake it up
        window.document.createElementNS = function(ns, tagName) {
                var elem = doc.createElement(tagName);  
                elem.getBBox = function() {
                        return {
                                x: elem.offsetLeft,
                                y: elem.offsetTop,
                                width: elem.offsetWidth,
                                height: elem.offsetHeight
                        };
                };
                return elem;
        };

        // Load scripts
        jsdom.jQueryify(window,'http://code.jquery.com/jquery-1.4.1.js', function(w,jq) {
                script.src = 'file://' + __dirname + '/highcharts/highcharts.src.js';
                script.onload = function() {
                        if (this.readyState === 'complete') {
                                callback(window);
                        }
                }
        });
}

function render(options, completed) {
        createHighchartsWindow(function(window) {
                var $   = window.jQuery,
                        Highcharts      = window.Highcharts,
                        document        = window.document,
                        $container      = $('<div id="container" />'),
                        chart, svg, convert, buffer;

                $container.appendTo(document.body);

                // merge options
                var totalOptions = options[0];
                for (i = 1; i < options.length; ++i) {
                  $.extend(true, totalOptions, options[i]);
                }
                chart = new Highcharts.Chart(totalOptions);

                svg = $container.children().html();

                // Start convert
                convert = spawn('convert', ['svg:-', 'png:-']);

                // Pump in the svg content
                convert.stdin.write(svg);
                convert.stdin.end();

                // Write the output of convert straight to the response
                convert.stdout.on('data', function(data) {
                        var prevBufferLength = (buffer ? buffer.length : 0),
                                newBuffer = new Buffer(prevBufferLength + data.length);

                        if (buffer) {
                                buffer.copy(newBuffer, 0, 0);
                        }

                        data.copy(newBuffer, prevBufferLength, 0);

                        buffer = newBuffer;
                });

                // When we're done, we're done
                convert.on('exit', function(code) {
                        completed(buffer);
                        console.log("done 3");
                });
        });
}

exports.render = render;

test.js

var hc = require('../lib/node-highcharts');
var fs = require('fs');

var options = new Array();
options.push({
  series: [{
    animation: false,
    data: [1,2,3,4,5]
  }]
});

options.push({
  chart: {
    defaultSeriesType: 'column',
    renderTo: 'container',
    renderer: 'SVG',
    width: 800,
    height: 600
  }
});

hc.render(options, function(result, err) {
        fs.writeFile('chart.png', 'result', function() { console.log('done 2'); });
});
console.log("done 1");