Joseki is a server for publishing RDF models on the web. Models have URLs and they can be accessed by query using HTTP GET. Joseki is part of the Jena RDF toolkit.
Joseki provides a coarse-grained RDF WebAPI that is based on extracting a subgraph from the published RDF. The extracted RDF can then be processed locally with the fine-grained API provided by Jena.
There are operations for adding and removing subgraphs from the target RDF source, allowing collaborative applications based on shared models.
Joseki is extensible: new query languages and new operations can be added without modifying the core system.
Joseki is open source and has a BSD license.