Creator: Matt Mullenweg
Percentage of websites powered by Wordpress: 32% (w3Techs)
Hosted WP: Wordpress.com (limited themes, plugins and functionality)
Open Source Software: Wordpress.org (Full source code to use in any manner)
Creed: Wordpress Foundation
Wordpress is a Content Management System or CMS. It was originally created as a blogging platform but has evolved into the most popular web site platform for amateurs and advanced users alike. Wordpress is open source which means the entire platform, files and programming is available to Wordpress theme builders, plugin authors and web developers. This results in a plethora of available add-ons and tools for almost any need.
Because of its popularity, flexibility and supporters, it has become the choice of nearly 1/3 of all website owners.