Freelancer ID website is using open source technologies like: PHP (Drupal), jQuery. The reason for being interested in using open source is because they are supported from thousands of developers, better in performance and spead, free to use and giving more experience for users and developers.

 The Most recent Freelancer ID project is: Easy Gallery, a jQuery plug-in.

Open Source:
Freelancer ID is currently using an open source framework to run this website. It's because this framework used is the most porpular and the most secure. Working with Drupal in Freelancer ID made the web development easier.
Working with open source projects is safer and more flixible. Open source community supports open source projects and keeps them up to date with security, performance, usability, flixibility and realibility.
Also, all open source projects are free, easy to find and  useful.

Some of these open-source projects used in work: PHP, MySQL, jQuery and Opensource frameworks.

PHP & MySQL:
Why using PHP? Well, using PHP is because it's faster  and more secure. It's also deployed in Apache server, which is fast and secure environment.
Why using MySQL? because of its consistent fast performance, high reliability and ease of use.

JavaScript & jQuery:
All web application and websites depending on Client-side scripting for sending requests, validating, customizing and animating the Front-End for visitor. The Client-Side Script (JavaScript) is the script can do more than you think on the clients web browser.
Because browsers not all the same and some does not support some JavaScript, and because the rendering is defferent between brwosers, jQuery team created a library that support all web browsers and most of browser versions.

jQuery is a JavaScript Library that simplifys developing JavaScript and makes JavaScript more flixible. To see some work on jQuery, please visit jQuery.com or see the blog: http://blog.freelancer-id.com