This style of network has the property that you can take two independent CJDNS networks, link them together, and all nodes are mutually addressable/routable. This is in contrast to The Internet, whose addressing is centralised on IANA.
cjdns is moderately active, though most links between nodes are via an overlay on top of the public Internet. The goal is to have physical/wireless links between geographically close nodes.
Use https://peers.fc00.io/ to find a cjdns node geographically close to you.
Decentralized protocols such as ipfs/scuttlebutt work particularly well on cjdns, as a file shared on ipfs in one network, will automagically become available on another network, once those networks are linked.
As I understand it, there was some way to de-anonymize traffic to a certain extent (which is still far better than the current situation), and that turned off some of the "purists" which is just a shame. From a practical perspective, even with some issues, getting rid of BGP is more than enough of a benefit.
I can't express enough how brilliant CJDNS is to me, it's really a magical idea. Which is not to say there won't be potential issues (even potentially existentially damning issues), but wow. I'd love to see this project move forward and get more attention. It's the first thing I've seen that really made me think about how we could design a better internet than the one we have today.
FWIW, I'm already happy to just nominate the CJDNS project as a potential winner of this prize, already.
IPFS and blockchain are technologies that are built on top of the internet - they assume a network connection already exists.
I wont speak for blockchains. Call them by the boring name as "Append-only databases with a consensus mechanism on what to add, with a proof-of-something to affirm that work of some soft was done".
IPFS is different. They have already planned that IP4 isn't the next thing. Or IP6, or IP8, and on. They created what they call a MultiAddr that encodes the protocol definition to explain to peers and IPFS what protocol stack to use, and then lay IPFS on top of that.
Obviously when a new protocol comes into play, they add a new multiaddr type for the new protocol, and off you go.
My gut feeling is that to create a long-term platform (rather than a point solution) we'd have to refit many extant application protocol stacks with CRDTs and reconceptualised crypto. Although for this contest I'd be imagining something less advanced, maybe a drone-based 4G hotspot loitering over communities with a copy of Wikipedia, a camera trained to detect signs of urgent distress, and a store-and-forward microblogging service like some automated Postman.
Someone should call Elon Musk and Vint Cerf about it, too, because I see many similarities between the outcomes for this and the outcomes for the Interplanetary Internet  which has been an ongoing research effort for years.
Suppose you had a distributed emergency IP radio network available that could provide 56Kb as long as at least one solar powered node per square kilometer was working. It would deliver VoIP and SMS, plus slow data connections. It would have HF links for long-haul connections even if telco services were unavailable. Who would use it?
FEMA tried distributing HF radios to first responder agencies, as a backup in case everything else went down. They can't even get most agencies to turn them on and talk for a monthly test.
People had a pretty good go at this in the early 2000s, when WiFi arrived on the scene. Most of those networks died and the ones that remain never took over the world . The sticking points in the efforts that I was involved in were:
1) Hassle in obtaining and setting up the hardware (particularly permanent antennas).
2) Lack of density, meaning it was hard to find others to connect to.
3) Address allocation and routing never really worked out, due to the need for central coordination.
I've been thinking about it ever since... Lots of ideas, but no 100% practical solution (yet).
It'll be interesting to see what happens this time, after 15 years of further development.
I think that the real solution requires caching, lookups, and multiple types of access through fingerprinted (sorry, can't say "secure") forwarding and proxying. It's a big task, but I do think that a small example could be built within the next year.
Heck, even LoRa, with the right software behind it could be a contender, if married to the correct technology.
Hm. That gets me thinking.
Web centralization is another problem and one I'm more worried about. Google and facebook control so much of it and they are so opaque.
What's a problem that only a decentralized web can solve?
- Privacy? (Most) People don't care. Irrelevant.
- Security? (Most) People don't care. Irrelevant.
Even Bitcoin and other cryptocurrencies would be irrelevant if it were not for their volatility, resulting in speculation, creating a feedback loop.
Education and messaging are obviously required to make the general public care but even companies like Slack went through this phase where they had to educate people about the product. But tbh, the real problem is that the solutions just aren't good enough and convenient. Tell me today, what is a good solution for me or average joe to keep all my data to myself without giving it to the big G and at the same time have a good experience sharing it with friends and family? I would love to hear proper solutions.
For example, people would _love_ to use firefox for privacy and security reasons but they aren't because firefox is not good enough compared to chrome.