WordPress is a free, open-source content management system founded in May 2003 by Matt Mullenweg and Mike Little as a fork of the dormant b2/cafelog blogging platform. Written in PHP and paired with a MySQL or MariaDB database, WordPress powers roughly 43% of all websites on the internet and over 60% of the global CMS market, making it the dominant publishing platform for individual creators, small businesses, and enterprise marketing teams alike.
WordPress exists in two related forms: WordPress.org, the self-hosted open-source software released under the GPL, and WordPress.com, the commercial managed-hosting service operated by Automattic — the company Mullenweg founded in 2005 to commercialize the ecosystem. Automattic's portfolio has since expanded to include Jetpack, Akismet, WooCommerce, and Tumblr, and the broader WordPress economy supports a multi-billion-dollar plugin and theme market with category leaders in commerce (WooCommerce), 📝Search Engine Optimization (SEO) (Yoast, Rank Math), forms (Gravity Forms, WPForms), and page-building (Elementor, Beaver Builder).
WordPress is what I built my first niche site on — stonermovies.net in 2012 — and the framework I managed 20+ sites through over the next two years. I ran the Ghost Influence blog on it before departing for Webflow in 2016, and have only circled back once since for a one-off project. It's a bit old and tired at this point.