Bittorrent uses a DHT called Kademlia to help bittorrent clients find peers. I've been meaning to fully understand bittorrent for some time now. I realized that focusing too much on clients/peers was a mistake; I should be focusing more on Tracker software.
https://en.wikipedia.org/wiki/Comparison_of_BitTorrent_tracker_software
Anyone here familiar with any trackers? LOL @ 2 being written in PHP. It seems like they've been slowly going the way of the dinosaur, outside of private trackers.