Freebase (ConceptTopic, 9)
From Compile Worlds
Freebase is essentially a crowdsourced database, where anyone can edit any "facts" in the database, with articles imported in bulk from many data sources such as Wikipedia. The main difference between Freebase and Wikipedia is that it's entirely machine-readable and as such, is much more formalized and sure takes some getting into. Also, it has no notability requirement, which means we can document such topics as Bunny Must Die and Touhou Mother on it, so yay! It was first released to the public in 2007, and was acquired by Google in 2010. Let's hope that the latter can sort out its current issues with slowness...
Interestingly, the fundamental concepts of Freebase are pretty much exactly what Keiji wanted to do for the ontology system in Kawachan. He was planning to eventually make a separate website for this, but never got around to it. Now he doesn't need to bother since Freebase is already that website, so now he instead plans to write some new sidebar widgets to bring in Freebase information, for example about fictional characters, into Kawachan infoboxes.
You can get started on Freebase by looking for the "freebase" link in the "alternates" sidebar widget on many pages right here on Compile Worlds. For example, there's one on this very page.