ActivityPub

ActivityPub

Pros

• Real time capable and bidirectional (do we need this?)

• Modern

• Used by Mastodon and other “fediverse” projects

Cons

• Complex

• Not widely adopted (outside of “fediverse” circles)

• Harder to deploy as a “static” file

RSS

RSS 2.0 Specification (version 2.0.11)

Podcast RSS feed requirements - Apple Podcasts for Creators

Pros

• Widely used (for podcasting and blogs)

• XML is extensible by design

• Can be served up as a static file

Cons

• XML is falling out of favour

• Badly specified

Atom

Atom Publishing Format and Protocol (atompub) - Documents

Pros

• Tries to fix the short-comings of RSS

• Can be served as a static file

• Can be bi-directional (do we need this?)

Cons

• XML

• Not as widely used as RSS

• More complex than RSS

JSONFeed

JSON Feed

Pros

• Minimal Standard (like RSS)

• Replaces XML with JSON

Cons

• Not widely used

• Not standardised by a recognized standards body (e.g. W3C)

WebSub

WebSub

(note: this adds push notification protocol to Atom)

Pros

• Simpler than ActivityPub

Cons

• Is this being used anywhere?
  

Sersia

http://searsia.org/protocol.html

Pros

• Made for federated search

Cons

• Not standardised, tied to a particular implementation