Notable companies and organizations that primarily use HTML, JavaScript, Python, Java, Ruby, or PHP include a wide range of tech giants and startups. For instance, HTML and JavaScript are widely used for web development by companies like Google, Facebook, and Amazon. Python is extensively used by companies such as Instagram, Spotify, and Dropbox for its versatility in various applications. Java finds extensive usage in large-scale enterprise systems utilized by financial institutions like Goldman Sachs and JPMorgan Chase. Ruby is popular among startups like Airbnb and GitHub due to its simplicity and ease of use. Lastly, PHP is commonly employed for web development by companies like WordPress and Slack.