Recently, I read a lot of papers making use of Wikipedia and also other different knowledge bases. Therefore, I collect some common ones which may be helpful for future use.
ConceptNet is a semantic network containing lots of things computers should know about the world, especially when understanding text written by people.
a lexical knowledge base of about 25,000 words grouped into an ontology of synsets
a social database of 1,450 concepts
a taxonomy of about 127,000 concepts extracted from Wikipedia’s category links
It contains about 12 million concepts learned iteratively from 1.68 billion web pages in Bing web repository.
It contains over 10 million geographical names and consists of over 9 million unique features whereof 2.8 million populated places and 5.5 million alternate names.
a semantic knowledge base of 149,162 instances derived from Wikipedia, WordNet and GeoNames, and ProBase