ActivityPub aka The Fediverse

Introduction

Social media is usually (by the time I write this post) represented by big tech companies that control the content and data generated from the users of the platform. However, recently, we’re seeing a shift towards decentralized alternatives that may change the way we interact with social services.

When choosing a social network, we usually have three main considerations:

• Format: networking, microblogging, link-aggregator, media sharing, short videos, etc
• Content: what content is being produced, and who’s interacting with it
• Owner: who dictates the rules and owns the data

The common pattern is to usually have only one or two alternatives for each social media format as we know: Facebook, Twitter, Reddit, Instagram, YouTube, TikTok; all owned by huge companies. People tend to go where the content is, but what if content could be shared across media platforms?

Meet the ActivityPub protocol

ActivityPub is an open, decentralized social networking protocol. It provides a client/server API for creating, updating, and deleting content, as well as a federated server-to-server API for delivering notifications and content. It was developed by the W3C Consortium and launched in 2018.

In summary, ActivityPub allows social networks to integrate and share stuff. This represents a decentralized model, where the content is spread across multiple “instances” but can be accessed by anyone in the “federated” network.

Implementations

Here are some open-source implementations of the ActivityPub:

• Mastodon: microblogging
• PeerTube: video platform
• Pixelfed: image and video sharing
• Lemmy: news aggregators and discussion forums

For each one of these, you can choose different instances to create your account and interact with content from all of the other connected/federated instances. The instance you choose will hold your data and moderate the content generated by it’s users and communities.

The instance owner can also decide whether or not block communication with other instances. If this happens, content is not accessible from one to the other and vice-versa. This process is called “defederation” and can happen when there’s a lack of trust between different instances, and/or to prevent spam, illicit activities, and so on.

The future of the Fediverse

The future of the universe of ActivityPub implementations (also known as Fediverse or Federated universe) is unknown. The reality is that we have a mix of open-source applications, and Meta is coming to the game with Threads. Here are a few questions that only time can answer:

• How the current fediverse (open-source projects) will react to the addition of Threads? Will we see a mass “defederation”?
• What’s Meta’s goal with federation? They’ll have access to a lot of user data for free, but will this be enough? Can we expect an Embrace, extend, and extinguish strategy?
• What’s the next “big addition” to the fediverse? Can we expect Reddit, Twitter, and other media companies to have their own implementations of the protocol?