freebase-gridworks - Project Hosting on Google Code
http://code.google.com/p/freebase-gridworks/

"an open data cleansing tool"

Freebase Gridworks is a power tool that allows you to load data, understand it, clean it up, reconcile it internally, augment it with data coming from Freebase, and optionally contribute your data to Freebase for others to use. All in the comfort and privacy of your own computer.