WordPress is a free and open source blogging tool and a content management system (CMS) based on PHP and MySQL, which runs on a web hosting service. Features include a plug-in architecture and a template system.
WordPress is used by more than 18.9% of the top 10 million websites as of August 2013. WordPress is the most popular blogging system in use on the Web at more than 60 million websites.
Please check my WordPress extensions.