Tribler is O.G. legit. Created in 2005 originally as a part of a research paper- I believe- around trying to create "fairer" allocation of bandwidth in BitTorrent (itself from 2001). Words like "incentivization" and "reptuation" dot their work for many years.

Tribler has continued to be one of the most leading edge pieces of p2p software on the planet. It went on to pioneer p2p search, streaming partially completed videos, live-streaming, a range of privacy/security enhancements, tagging, moderation.

In 2012 they dubbed their efforts "4th Generation P2P", encompassing a couple of these goals, many of which were already underway. I believe they've succeeded on all these fronts, & have only continued pushing further since. https://www.tribler.org/4thGenerationP2P/

The team has been up to ongoing cutting edge research for a long time. Their ability to create p2p search is, still, basically unparalleled in this world.