WordPress is a free and open-source content management system (CMS) written in hypertext preprocessor (PHP) language and paired with a MySQL or MariaDB database with supported HTTPS. Features include a plugin architecture and a template system, referred to within WordPress as "Themes". WordPress was originally created as a blog-publishing system but has evolved to support other web content types including more traditional mailing lists and Internet fora, media galleries, membership sites, learning management systems (LMS) and online stores. WordPress is used by 42.8% of the top 10 million websites as of October 2021.