What can ActivityPub do that RSS can't?
What can ActivityPub do that RSS can't?
I know they're quite different technically. But practically, what does ActivityPub unlock that was not previously possible with RSS and basic web tech stack?
I think I have an idea of the answer. RSS may provide a way for users to "subscribe" to content from a feed, equivalent of following and putting it in a unified feed.
But it does not have a way for users to interact with the poster, like comments or likes. This may be possible with a basic web stack though, but either users will have to make accounts on every person's site, or the site has to accept no user auth. (but this could be resolved with a identity provider standard, like disqus does)
I suppose another thing activityPub does is distribute content to multiple servers. Not sure if this is really desirable though?
Anyways, did I miss anything?
Basically, RSS as you said, is a one way street. There is no feedback. It's not so much communication, but broadcasting.
That's most of it. ActivityPub also makes it possible to know who is subscribed. It's very hard to count how many people are subscribed to an RSS feed.
Not really. They're making requests, probably at least once a day. That makes it very easy to count active users. With subscribers, you can have a big number, but they're not necessarily all active, and unless they're on your instance, you can't see how often they're reading.
This may be possible with a basic web stack
"basic web tech stack" is quite a bit hand-wavy, don't you think?
Yeah, indieweb sites could do a lot of things: authn and authz, content syndication, backlinking, Social Graph, etc. But none of them had been standardized and put into one single protocol. ActivityPub is precisely this protocol.
Saying that "we can do that with a basic web stack" is not that different from saying "we can have a protocol to publish XML content without styling using a basic web stack, why do we need RSS or Atom?"
You're right, it is hand wavy.
But I think it is valid for every blog to have things like comments and likes in their own way, if they're okay with users not being authenticated.
But yes, it makes sense this is where activity Pub shines.
One more difference is that RSS is polling based, meaning that subscribers have to actively ask every hour or so if thre is new content.
On the other hand, ActivityPub knows who is subscribed and can actively distribute new content to other servers who can in turn send push messages to their users, letting you know about new content within seconds.
So activityPub uses push architecture to push to other servers / instances, but it doesn't push to users does it? I would imagine from instance to user, it is still pull based.
So effectively it's a load distributer thing, I suppose, right?
As far as I know, ActivityPub only applies to server to server communication. Still, many applications that implement ActivityPub (for example Mastodon) do use push notifications for their clients.
RSS readers just fetch a certain .rss file from a website and render that for you. RSS is a simple tool, it's not even comparable to something like ActivityPub.
You also have no way of discovering new stuff, you have to find them yourself. Whereas with ActivityPub you can. Nor can you interact with the feed objects (comment, like, etc).
I'd argue that discoverability on fediverse kinda sucks.
There's the network effect kind of discoverability, where someone you follow reposts something, and you discover this new something and possibly follow it. RSS has all the technology necessary to make this happen.
There's the discoversbility where you sort by "New" or "all" on your fediverse feed. I suppose that is discoverability that RSS doesn't have natively, but I'd argue this sucks pretty badly.
Last, there's the search engine type of discoverability, where you search through fediverse communities or users. This isn't native to ActivityPub, and a RSS search engine can be implemented pretty similarly.
In summary, So activityPub might have some discoverability paths, but the one that RSS doesn't have natively, I argue sucks and is not the right way to do it.
Respond and interact with content. Whatever it may be. In most sites, that means using their singular platform with their rules. With Activity hub, it means using many potentially different platforms to communicate.
I personally use both rss and activity hub. Works pretty well. One to inform and one to communicate with.
The really intriguing thing about ActivityPub, at least to me, is it's capability and potential to be a bridge for many other protocols.
For example, here's ActivityPub via email: https://apubtest2.srcbeat.com/apas.html
That page also references the longstanding NNTP(Usenet)-email bridge that existed for the linux-kernel mailing list, so we could get ActivityPub to Usenet.
In fact there are a couple of RSS->Mastodon projects out there already, such as https://github.com/dariusk/rss-to-activitypub or https://github.com/jehna/mastofeeder
Do you know if they're an ActivityPub-BlueSky bridge in the works?
It's already up and running. I follow several Bluesky users in my Mastodon, some Bluesky people follow me as well.
It has to be manually enabled on both sides though.
Is there something about activity Pub that enables it do this, that other protocols or architectures wouldn't have?
Depends on your POV.
In one sense, if ActivityPub can be a bridge between two protocols (e.g. RSS vs email) then it's always technically possible to cut out the middle man. In that sense, no not really.
From my POV though ActivityPub shines because it's more content agnostic. RSS is specific to feeds and posts, while email is for email, Bluesky is Bluesky (twitter), etc, but ActivityPub can handle video (peertube), images (pixelfed), forums - including likes and downvotes (Lemmy), microblogging (Mastodon), etc. (Note that the ActivityPub to email implementation I mentioned currently doesn't handle likes/downvotes for example.)
With the possible exception of email, I'd also say that ActivityPub has something these other protocols do not - ownership over your own data. If you run your own instance for yourself, you always retain a copy of your content - you don't have the situation of ello.co where if the site suddenly goes down without warning you lose years of work. Even if you use someone else's instance, if that goes down you may be able to recover your content from another instance that was federating to it (retrieving content posted to kbin.social from the copy at fedia.io for example). That's the beautify of federation.
(This is also true of traditional email, but things like gmail and Outlook - where the email is simply hosted on someone else's server - are moving away from that.)
ActivityPub acts like two-way RSS
Anyways, did I miss anything?
I think the big problem in link aggregation is how to sort/prioritize content for the end user. RSS does not provide a way to do this, nor should it as far as I'm concerned. It should simply be about public content being tagged in a standardized way for any app to come along and organize it using whatever algorithm.
A simple RSS reader has the problem that the more prolific sites will tend to flood your feed and make it tedious to scroll through miles of links. Commercial news portals try to learn your tastes through some sort of machine learning algorithm and direct content accordingly. This sounds like a good idea in theory, but tends to build echo chambers around people that reinforce their biases, and that hasn't done a lot of good for the world to put it mildly.
The lemmy approach is to use one of a number of sorting algorithms built atop a crowd-sourced voting model. It may not be perfect, but I prefer it to being psychoanalyzed by an AI.
Btw there was a post from about a month ago where someone was offering to make any RSS feed into a community. I've subscribed to a few of them and it's actually pretty awesome.
From what I see, ActivityPub doesn't seem to solve the problem of sorting or prioritizing content. In fact, I believe RSS wins here, because it is easier to do this on the client side with RSS, as it is assumed the client has all the content from the RSS feed without any biased order, whereas with activity pub, it varies by provider and instance.
Sorting and filtering can be done well on the client side, and the plus side is the user can have a ton of choice here. It just so happens that our algorithms for that in the open source world are no match for the addiction-inducing ones of Twitter and others.
You raise a good point that it would be nice to have more control over which group of communities you are drawing from at a given time. (Is there a way to group subscriptions and switch between them?) It’s a bit disconcerting to see 5 tech headlines and then suddenly something about the war in Ukraine or whatever. It jars my train of thought. With an RSS client, you can group feeds however you want.
That said, my experience with RSS readers is not quite so idyllic. In the end, rather than having nicely partitioned feed groups by topic, I wind up having to separate the ones that produce content frequently but with a poor signal-to-noise from those that post once in awhile but are generally worth your time. With something like lemmy, people are helping you do the work of finding the more interesting content from that site that posts every 10 minutes.
- If you don't have a specific interest and/or lack the skill of finding new content that you like , RSS mostly won't help you unless it has a " suggestion " feature , while on ActivityPub ( or any other social media ) you can find new content that might or might not suit you just by browsing
- RSS is read-only , ActivityPub is not
Activitypub can include private messages