Mastodon is a free, open-source social network server based on open web protocols like ActivityPub and OStatus. The social focus of the project is a viable decentralized alternative to commercial social media silos that returns the control of the content distribution channels to the people. The technical focus of the project is a good user interface, a clean REST API for 3rd party apps and robust anti-abuse tools.
No vendor lock-in: Fully interoperable with any conforming platform
It doesn't have to be Mastodon, whatever implements ActivityPub or OStatus is part of the social network!
Real-time timeline updates
See the updates of people you're following appear in real-time in the UI via WebSockets. There's a firehose view as well!
Federated thread resolving
If someone you follow replies to a user unknown to the server, the server fetches the full thread so you can view it without leaving the UI
Media attachments like images and short videos
Upload and view images and WebM/MP4 videos attached to the updates. Videos with no audio track are treated like GIFs; normal videos are looped - like vines!
OAuth2 and a straightforward REST API
Mastodon acts as an OAuth2 provider so 3rd party apps can use the API
Fast response times
Mastodon tries to be as fast and responsive as possible, so all long-running tasks are delegated to background processing
Deployable via Docker
You don't need to mess with dependencies and configuration if you want to try Mastodon, if you have Docker and Docker Compose the deployment is extremely easy