There are 6 repositories under activitystreams topic.
Fast, fun, small ActivityPub server.
:bulb: dokieli is a clientside editor for decentralised article publishing, annotations and social interactions
Powering connected social communities with open software.
ActivityPub for WordPress
Activity Streams 2.0
A PHP implementation of ActivityPub protocol based upon the ActivityStreams 2.0 data format.
Flask-based ActivityPub server
An attempt to build a spec-compliant ActivityPub core library.
Activity Feed, Timeline, News Feed, Notification Feed with MongoDB, Node and CRDTs
Modular implementation of ActivityPub in C#
An OStatus library written in Go
An ActivityPub server that reblogs all the statuses of certain actors.
Hanatachi is a free, open-source social network server for federated blogging
An inofficial proposal for ActivityPub - JSON Schemas (draft 07)
ActivityPub JS/TS models
A .NET implementation of the Activity Streams vocabulary in the form of classes that can be serialized/deserialized using System.Text.Json
Activity Streams is a simple specification used to describe social actions around the web.
alternative docs for ActivityStreams 2.0 vocabulary
Activity Streams validation for Typescript
Presentations on: golang and ActivityPub
Command-line tools for interacting with the pump.io API
Simple, post-only ActivityPub implementation in PHP
Specifications to implement intent feature for ActivityPub
Modeling non-verbal communication as an ActivityStreams extension
Index of open-source ActivityPub projects using C# or .NET