WordPress (WordPress.org) is a content management system (CMS) based on PHP and MySQL that is usually used with the MySQL or MariaDB database servers but can also use the SQLite database engine. Feature’s include a plugin architecture and a template system, referred to inside WordPress as Themes. WordPress is most associated with blogging (its original purpose when first created) but has evolved to support other types of web content including more traditional mailing lists and forums, media galleries, membership sites, learning management systems (LMS) and online stores. WordPress is used by more than 60 million websites, including 33.6% of the top 10 million websites as of April 2019, WordPress is one of the most popular content management system (CMS) solutions in use. WordPress has also been used for other application domains such as pervasive display systems (PDS).