Wikidata

Wikidata (.org) is a project by WikiMedia Foundation initiated in the start of 2012. It aims to provide for data ( such as infobox data ) a central repository similarly as the commons does for files. Example of wikidata interface for humans: wikidata-test-repo on Helium

One of the aims of the project is to make the data accessible to computers as well as humans.

Also interwiki ( inter-language ) links will be hosted in Wikidata removing much redundancy and error-proneness.

Obviously a main source of reference level data.

More info: m:Wikidata