I2P is a self-contained thing - once you are on I2P you can reach others who are also on I2P. Some I2P users run an outproxy, if you use an outproxy for anonym

I2P is a self-contained thing - once you are on I2P you can reach others who are also on I2P. Some I2P users run an outproxy, if you use an outproxy for anonymized Internet access, the outproxy has access to your web traffic just like a Tor exit node does. Tor will change circuits and your exit node periodically, if you use an I2P outproxy you'll have that outproxy's IP until you stop using it. Also I2P (at least last I checked it out a few years ago) has a built-in torrent -over-I2P client.