JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://code.highcharts.com/highcharts.js"></script>
<script src="http://code.highcharts.com/modules/exporting.js"></script>



<div id="container" style="min-width: 400px; height: 400px; margin: 0 auto"></div>

JavaScript

$(function() {
    var chart,
        list = {},
        items = [];

    $.getJSON('http://fronteers.nl/congres/2011/attendees.json', function(data) {
        $.each(data.fronteers2012.andAllTheirOtherData, function(){
            if (!list[this.country]) {
                list[this.country] = 0;
            }
            
            list[this.country]++
        });
        
        $.each(list, function(k, v) {
            items.push([k, v]);
        });
            
        makeChart(items);
    });
    
    function makeChart(data) {
        chart = new Highcharts.Chart({
            chart: {
                renderTo: 'container',
                plotBackgroundColor: null,
                plotBorderWidth: null,
                plotShadow: false
            },
            title: {
                text: 'Fronteers 2012 by Country'
            },
            tooltip: {
                formatter: function() {
                    return '<b>'+ this.point.name +'</b>: '
                        + this.percentage.toFixed(2) +' %';
                }
            },
            plotOptions: {
                pie: {
                    allowPointSelect: true,
                    cursor: 'pointer',
                    dataLabels: {
                        enabled: true,
                        color: '#000000',
                        connectorColor: '#000000',
                        formatter: function() {
                            return '<b>'+ this.point.name +'</b>: '
                                + this.percentage.toFixed(2) +' %';
                        }
                    }
                }
            },
            series: [{
                type: 'pie',
                name: 'Browser share',
                data: data
            }]
        });
    }
});