I did some more looking into this because I've been rather out of the loop, but here's a quick lay of the land:
- I2P - Invisible Internet Protocol - The focus here is on anonymous browsing of the clearnet (public internet/web). It does not do distributed data nor does it promise to anonymize publishing. It is Java-based, which is a strange choice, but so be it. Adoption is modest.
- Tor/Onion - The focus here is on anonymous browsing and anonymous hosting. Tor supports clearnet and darknet browsing; darknet is available via "onion routing," which uses its own URL format and routes entirely within the Tor network. This one has the widest adoption, probably because it's popular among 4channers. It's also the easiest to use as there's a Firefox bundle that's essentially "Tor in a box." You run it and you're using Tor, period.
- Freenet - Very old, about as old as I2P. This one has the distinction of enabling anonymous browsing, anonymous hosting, and data redundancy. You can publish on Freenet and, as long as at least a few people accessed what you published, if you go offline others can still view your content, as it uses a distributed data model. This is probably its coolest feature. Unfortunately, adoption is low-ish. Maybe above I2P but well below Tor. Due to the nature of its network, it is for browsing darknet content specifically.
- Zeronet - This is the newest one on the list. Someone had the bright idea to turn a blockchain into web hosting. This is actually not a bad idea! The big problems with blockchains are mostly around energy usage for crunching numbers to mine coins. Services that aren't fixated on mining coins don't have this problem, and so it goes with Zeronet. In practical terms, it works a lot like Freenet: it's peer-to-peer, decentralized, and continues hosting content even if the publisher goes offline. Since it uses a blockchain, anything published is signed in such a way that you can verify the provenance of any particular document (if you want.) This enables, for instance, secure anonymous communications. Like Freenet, this is a darknet service. Adoption seems good for its age but I think it's still below Freenet, at least.
I should explain a couple terms:
- clearnet -- This is the public internet, the one you're looking at right now. Any conventional web browser can access the clearnet. Just your run-of-the-mill world wide web (plus other services, but mostly we're looking at web browsing here.)
- darknet -- This is anything hosted online but off of the clearnet, requiring special software to access. It does not necessarily mean "illegal," though of course a lot of people use darknet tools to do illegal things. So, be careful using any such tools. You typically won't stumble across illegal content, just be aware that it is likely easier to find, so be wary.
An honorable mention here is Project Gemini, not to be confused with Google's Gemini product:
https://geminiprotocol.net/
The Gemini Protocol is essentially an attempt to return the web to its roots of static text-first content. No JavaScript, no cookies, no dynamic pages, none of that jazz. It requires a special browser but it is
not focused on anonymity for any party. It is simply an approach toward a more "retro" web experience.
