Since October 2007 Richard Cyganiak has been creating visual representations of the growing cloud of linked data sets. Linked data allows you to navigate directly from one item in one data source, to other related and relevant data items in another data source. That way linked data makes it possible to interpret data (as a piece of data can for instance point to another piece of data that contains its definition), or do queries across several data sets at once.

The W3C, the world wide web consortium responsible for web standards, has a SWEO community project called Linking Open Data. The visualizations of the linked data cloud are part of this project.

The maintainers, Richard Cyganiak, Anja Jentsch and Chris Bizer, of the linked data cloud have now decided to use CKAN for keeping the list of linked data sources. CKAN is an open source register to describe datasets. CKAN is used to power the back-end of various open data catalogues around the EU, most notably the data.gov.uk data catalogue of the UK government.

From the e-mail announcement:

"For drawing the next version of the LOD cloud, we have started to collect meta-information about the datasets to be included on CKAN, a registry of open data and content packages provided by the Open Knowledge Foundation.

In addition to basic meta-information about a dataset such as its size and the number of links pointing at other datasets, we also collect additional meta-information about the license of the dataset, alternative access options like SPARQL endpoints or dataset dumps, and whether there exist a voiD description of the dataset or a Semantic Web Sitemap.

So if your dataset is not listed yet and you want to have it included into the next version of the LOD cloud, please add it to CKAN until next Wednesday (September 8th, 2010).

Also, if we have collected wrong information about your dataset or if your dataset is only partially described up till now, it would be great if you could add the missing information."