What websites or servers do you know require external technology to run?

An example would be using a radio receiver to seek true random numbers from atmospheric noise, as mentioned here: https://www.random.org/faq/#Q1.3

Another examples is Cloudflare using lava lamps to enhance the creation of encryption keys: https://www.cloudflare.com/learning/ssl/lava-lamp-encryption/

What technology, other than regular computation and typically for a specific use case, do you know a website or other server is connected to?