There are many large and successful companies that use WordPress as their website platform, including some Fortune 500 companies. Here are a few examples:

1. Microsoft: Microsoft, one of the largest technology companies in the world, uses WordPress to power its corporate blog, where they share news, updates, and insights on their products and services.
2. General Electric: General Electric, a leading multinational conglomerate, uses WordPress to power its website, where they share information on their products, services, and initiatives.
3. Sony Music: Sony Music, one of the largest record labels in the world, uses WordPress to power its website, where they provide information on their artists, albums, and events.
4. News Corp: News Corp, a media conglomerate with holdings in newspapers, books, and television, uses WordPress to power several of its websites, including The Times of London and The Sun.
5. Time Inc.: Time Inc., a leading media company with a portfolio of iconic brands, including People, Time, and Sports Illustrated, uses WordPress to power several of its websites.
6. USA Today: USA Today, a leading national newspaper, uses WordPress to power its website, where they provide news, analysis, and opinions on a wide range of topics.
7. MTV News: MTV News, the news division of the music television network, uses WordPress to power its website, where they provide the latest music news and trends.
8. TED: TED, the nonprofit organization dedicated to spreading ideas, uses WordPress to power its website, where they host a library of talks on a wide range of topics.

These are just a few examples of the many large and successful companies that use WordPress as their website platform. WordPress is a powerful, flexible, and scalable platform that can be used by businesses of all sizes, from small startups to Fortune 500 companies.