Two other approaches, a bit messier but with bigger coverage: * ConceptNet (http://conceptnet5.media.mit.edu/ http://conceptnet5.media.mit.edu/), I think the f

Two other approaches, a bit messier but with bigger coverage: * ConceptNet (http://conceptnet5.media.mit.edu/ http://conceptnet5.media.mit.edu/), I think the first major attempt at a "messier" crowdsourced commonsense-facts database. Not a carefully designed hierarchical ontology like Cyc, but rather a large set of lightly curated statements about natural-language nouns and verbs. Has the pros and cons you might expect: better coverage, and easier to use, but less precision and a lot of ambiguity due to polysemy. * CMU's "Read the Web" (http://rtw.ml.cmu.edu/rtw/ http://rtw.ml.cmu.edu/rtw/) and U. Washington's "Open IE" (http://openie.cs.washington.edu/ http://openie.cs.washington.edu/), both projects that combine a shallow-parsing fact-extractor with web-scale crawling. They are truly gigantic, but the accuracy is not very high.