free base

Freebase or free base refers to the pure basic form of an amine, as opposed to its salt form. The amine is usually an alkaloid natural product. Free base is commonly used in organic chemistry and pharmaceuticals to describe the deprotonated amine form of a compound.

Freebase was a large collaborative knowledge base consisting of data composed mainly by its community members. It was an online collection of structured data harvested from many sources, including individual, user-submitted wiki contributions. Freebase aimed to create a global resource that allowed people (and machines) to access common information more effectively. It was developed by the American software company Metaweb and ran publicly since March 2007. Metaweb was acquired by Google in a private sale announced 16 July 2010. Google's Knowledge Graph was powered in part by Freebase.