I like the W3C WebSub standard (formerly known as PubSubHubbub) which uses RSS/Atom underneath to syndicate content. The only catch is that it requires a publicly visible URL for callback. This is great for services like Feedly but may not work for individual subscribers who just want to use a client application and not run a server with public facing URL. But maybe, this is better than running a Mastodon server because we can still have the benefits of a simple Atom format and protocol.
> I like the W3C WebSub standard (formerly known as PubSubHubbub) which uses RSS/Atom underneath to syndicate content.
While you can use Atom/RSS with WebSub, WebSub doesn't expressly use any particular syndication format (it can distribute any content directly, not just Atom/RSS feeds) and hasn't, IIRC, since one of the PubsubHubbub drafts (I think 0.3, but maybe 0.4.)
