OStatus is an open standard for distributed status updates that references a suite of open protocols including Atom, Activity Streams, PubSubHubbub, Salmon, Webfinger, that allows different messaging hubs to route status updates between users in near real-time.
OStatus federation was first possible between StatusNet installations, and later between StatusNet and MiniMe. Various other content management systems are still incomplete in their compliance to the full standard.
- GNU social (formerly StatusNet)
- Project Danube
- Project Nori
- OpenMicroBlogging - older federated microblogging specification, to be superseded by OStatus.