Cross-Platform Federation of Internet Infrastructures
By Chelsea Barabas, Neha Narula and Ethan Zuckerman:
"Cross-platform federation is important, because it enables individuals to speak to each other without subscribing to the same service or relying on the same codebase (and thus, the same developers). This is a critical aspect of enabling greater agency and choice for users, because it reduces the friction of switching from one platform to another. Instant messaging is an excellent example of this -- right now, if a user wants to switch to a new messaging application, then it’s unlikely that they’ll be able to communicate with their contacts who are using a different service. This wasn’t always the case. For example, XMPP is a protocol that lets different messaging services exchange messages. Google chat used to support XMPP, but recently opted out, possibly due to the fact that most users were not using the federated features to speak with their friends across different messaging services.
Today, most open source federated projects only focus on federating with other nodes in their network, not across services, or only with the most popular social media platforms like Facebook or Twitter. This is due in large part to the fact that federated platforms bear the additional burden of coordinating across different clients, which makes it tough for them to remain agile and adaptable over time. For example, Signal, a popular encrypted messaging application, opted for a non-federated protocol, because it proved too challenging for them to respond to user demand for new features when using federated models. According to Signal’s lead developer, Moxie Marlinspike, “It's undeniable that once you federate your protocol, it becomes very difficult to make changes. And right now, at the application level, things that stand still don't fare very well in a world where the ecosystem is moving
As a result of these challenges, open source platforms often cannot match the usability and quality of performance of privatized platforms like Facebook and Twitter." (http://dci.mit.edu/assets/papers/decentralized_web.pdf)
For a successful example, see Mastodon