Freebase is an open database of the world’s information. It is built by the community and for the community—free for anyone to query, contribute to, build applications on top of, or integrate into their websites.
NEPOMUK brings together researchers, industrial software developers, and representative industrial users, to develop a comprehensive solution for extending the personal desktop into a collaboration environment which supports both the personal information management and the sharing and exchange across social and organizational relations.
C. Cattuto, D. Benz, A. Hotho, and G. Stumme. The Semantic Web - ISWC 2008, Proc.Intl. Semantic Web Conference 2008, volume 5318 of LNAI, page 615--631. Heidelberg, Springer, (2008)