Hey, there is now an Anarchism public group on Nostr. Nostr is a very simple protocol which aims to become the ultimate decentralized social network, already fulfilling functionality of Twitter, Reddit (not very advanced tho), Twitch, Telegram and more. It is also uncensorable.
It is also more anarchist than the fediverse because your identity there is not bound to a server/domain which can be shut down or moderated at any time.
To join the group, you have to search for this ID: nevent1qqs05w7vklg8ewh4g7u8rafp3dsvtcw3j7v9j4v7n4k5fxxewaggjdspp4mhxue69uhkummn9ekx7mqpz4mhxue69uhkummnw3ezuerpw3sju6rpw4esz9rhwden5te0dehhxarj9ehhsarj9ejx2assy2425
On Android the app Amethyst is very good. With Nostr, the client handles everything. The servers are just dumb relays which don’t need to be trusted. That’s why there are a lot of different clients. Each one is implementing different aspects of the protocol and they are always evolving.
If you want to have a peek at the group you can also check here: https://coracle.social/chat/note1lgaued7s0ja023acw86jrzmqchsar9uct92ea8tdgjvdja6s3ymqa579ar
There are a LOT of Nostr resources available and you can decide how deep you want to dive into it. A very basic and easy introduction is https://usenostr.org/ . The devs website nostr.com also does a good job of getting the point across. There is an awesome list which can point you to any Nostr related resources like which clients to use and also what other introductory guides are availabe: https://github.com/aljazceru/awesome-nostr
Popular clients including web, desktop and mobile are also described here: https://nostr.com/clients
Note that Nostr is very decentralized and that some clients implement features which other clients don't (yet).
This video can also show you visually how the relationship between clients and relays/servers works: https://www.youtube.com/watch?v=yIccRIEr2gQ
I've updated the post with more resources. To answer your question: https://coracle.social/chat is a webclient where you can view the contents of this group without signing up. Actually, you shouldn't need to sign up in any client, as all of the data is available publicly, including messages in group chats. "Signing up" also just means on Nostr that you create a personal key that you can use to authenticate yourself in any client. No big deal if you create a key for some testing and then never use it again.
There are a lot of different clients, each implementing more or less of what's possible with Nostr. I specifically mentioned the android app because that one has implements a lot so you can get a better idea of what is possible (and it is also pleasant to look at), but if you just want to check out the group you can also use for example the webclient I linked above
it’s just that without an open web-first front end (like Mastodon), it runs the risk of becoming either yet another walled garden or yet another niche protocol (like Gemini) – people are getting tired of having to download even more single-use apps …
I don't see how it could ever become a walled garden, ALL of the content is publicly accessible on public servers/relays. The implemented crypto is so you can pay/donate to someone if you wish and there are also relays which you have to pay in order to post content there, but that is to avoid that a relay is spammed by bots. You don't have to pay those relays.
Gemini and Nostr are not comparable on a "niche-protocol" scale in my opinion, as Gemini is literally only for sharing text over the web while Nostr is hyper-extensible and has more and more use cases as time passes. So definitely not a single-use app. It is also endorsed and actively used by Jack Dorsey (former Twitter CEO with huge fan base) and Edward Snowden, again, not comparable with Gemini.