> I think far more interesting these days would be projects like Veilid, Hyphanet's Locutus

I have not assessed Veilid yet but it's on my list and at a first glance seems like a very serious and informed attempt. I'm personal friends with Freenet / Hyphanet's Ian Clarke and spoke with him about Locutus when he was just getting started. It sounded awesome then and I will give this a second look too, though when he explained it to me it sounded like it had the same limitations with deletion that Nostr or the global IPFS network would have. It does seem important to note here that both Veilid and Locutus are much less mature and battle-tested than libp2p and Tor and have less Lindy longevity (longevity as a function of age.) We already suffer a lot from being on the bleeding edge, so it's nice to limit the number of bleeding edge tools we use. Libp2p, notably, has been rock solid for us and barely a time drain at all, apart from some unexpected interactions with Tor which are mostly about the lack of an official first-class Tor transport, which is specific to our use case and should start to change soon when Tor's Arti is ready.

> and ultimately Nostr -- even though not truly P2P in that sense -- which already happens to have a first try going with nostrchat.io.

Nostr and Bluesky both seem very promising for the open-world use case of social networking, and it has been amazing to see Nostr grow so rapidly as a community. I am rooting for this project and we might use it someday in Quiet for public feeds. Timed deletion is the user requirement that drives me away from building Quiet on Nostr. Based on conversations I've had with users doing sensitive work (and based on my own experience as a founder of Fight for the Future) timed deletion is extremely important to team security, and for deletion to be meaningful one needs more control over where the data is relayed than what Nostr provides in the default mode. A group that wanted trustworthy timed deletion would have to control their own private Nostr relay. Technically, a Tor relay could subvert the timed deletion of some Quiet messages just by capturing all traffic, but this is much less of a worry.

> If P2P is something that is truly desired, I feel like projects like Briar (https://briarproject.org/how-it-works/) have solved this with Bramble (https://code.briarproject.org/briar/briar-spec/blob/master/p...) more eloquently than it could be done on top of IPFS.

Bramble could work for us and I would recommend that anyone look into it. Briar is probably the most similar thing to Quiet that exists right now. There are big differences between Quiet and Briar, but we could definitely build Quiet on Bramble if it adequately supports iOS. My worry would be its maturity as a tool for people building things other than Briar. That could be worth the risk though and I do recommend anyone else reading this thread look at Bramble if you are doing something similar.

> I could nevertheless imagine it being overtaken fairly quickly by other projects sporting a rather lightweight and more managable basis, that allows for increased development speed and ultimately for faster iteration on features that users might wish for (e.g. DMs, @-mentions, message deletion, mobile clients, you-name-it) -- without the need to invest heavily into e.g. performance (or reliability!) issues of the underlying framework.

This is definitely something we will keep an eye on, and thank you for the thoughtful advice! My guess is that as soon as we have a significant number of real users we will need to build things that don't happen to be supported by whatever stack we choose (whether that is our current stack, Bramble, Veilid, Automerge, etc.) So the question is what's the easiest one to maintain and adapt. So far libp2p and IPFS have both been good in that department: implementations in many languages, active development, an absence of major problems showing signs of maturity (especially in libp2p), etc.

Also, my 2 cents are (for anyone following along) that if I had to do this all over again I would use Tor + Libp2p + Automerge. Libp2p and Gossipsub are solid, flexible, and will be around a while. No need to reinvent the wheel. The conceptual framework behind Automerge and Briar/Bramble are pretty similar (sync state!) but the Automerge team exists to serve people building other apps, while the Bramble team mostly focuses on Briar AFAIK. What's nice about Automerge is that the community around it (Ink & Switch, Martin Kleppmann, and other academics) is all at the academic frontier, so the level of thought and anticipation of user needs that goes into their decisions is very thorough, even if the implementations lag behind the papers. If I was doing real-time p2p text editing I would also look at the Braid project (braid.org) and Seph Gentle's work on Diamond Types, since that's where the most thought has gone into the raw performance you need for text CRDTs that can handle large documents: https://github.com/josephg/diamond-types