For the chemistry term, see free base. For the music supergroup, see Freebass.
Web address
Commercial? No
Type of site Online database
Registration Optional
Available language(s) English
Content license Creative Commons Attribution License
Owner Metaweb Technologies (Google)
Alexa rank Steady 16,196 (June 2012)[1]
Current status Active

Freebase is a large collaborative announced July 16, 2010.

Freebase data is available for free/libre for database dump are provided for programmers.


On March 3, 2007, Metaweb publicly announced Freebase, described by the company as "an open shared database of the world's knowledge," and "a massive, collaboratively edited database of cross-linked data." Often understood as database model using World Heritage Encyclopedia-turned-database or entity-relationship model, Freebase provides an interface that allows non-programmers to fill in structured, or 'meta-data', of general information, and to categorize or connect data items in meaningful, or 'semantic' ways.

Described by Tim O'Reilly upon their launch, "Freebase is the bridge between the bottom up vision of Web 2.0 collective intelligence and the more structured world of the semantic web."[3]

Freebase contains data harvested from sources such as World Heritage Encyclopedia, ChefMoz, NNDB, and MusicBrainz, as well as individually contributed data from its users. The structured data is licensed under the Creative Commons Attribution License, [3] and a JSON-based HTTP API is provided to programmers for developing applications on any platform to utilize the Freebase data. The source code for the Metaweb application itself is proprietary.

Freebase runs on a database infrastructure created in-house by Metaweb that utilizes a graph model. This means that instead of using tables and keys to define data structures, Freebase defines its data structure as a set of nodes and a set of links that establish relationships between the nodes. Because its data structure is non-hierarchical, Freebase can model much more complex relationships between individual elements than a conventional database, and is open for users to enter new objects and relationships into the underlying graph. Queries to the database are made in Metaweb Query Language (MQL) and served by a triplestore called graphd.[4]


Danny Hillis first described his idea for creating a knowledge web he called Aristotle in a paper in 2000.[5] But he said he did not try to build the system until he had recruited two technical experts as co-founders. Robert Cook, in parallel computing and database design, is Metaweb’s executive vice president for product development. John Giannandrea, formerly chief technologist at Tellme Networks and chief technologist of the Web browser group at Netscape/AOL, is the company’s chief technology officer.[6]

Originally accessible by invitation only, Freebase opened full anonymous read access to the public in its alpha stage of development, and now requires registration only for data contributions.

On October 29, 2008, at the International Semantic Web Conference 2008, Freebase released its RDF service for generating RDF representations of Freebase topics, allowing Freebase to be used as Linked Data.[7]

Organization and policy

Freebase's subjects (which often correspond to a World Heritage Encyclopedia article) are called topics and the data stored about them depend on their type, how they are classified. For example, an entry for

Freebase's ontologies (structured categories), known in Freebase as "types" — are themselves user-editable.[3] Each type has a number of defined predicates, called "properties".

[U]nlike the W3C approach to the semantic web, which starts with controlled ontologies, Metaweb adopts a folksonomy approach, in which people can add new categories (much like tags), in a messy sprawl of potentially overlapping assertions.[3]

In this manner, Freebase differs from the wiki model in many ways. Users can create their own types, but these types aren't adopted in the 'public commons' until promoted by a Metaweb employee. As well, users cannot modify each other's types. The reason Freebase can't open up permissions of schemas is because external apps rely on them; thus changing a type's schema, for instance by deleting a property or changing a simple property, might break queries for API users and even within Freebase itself - in saved views, for example.

Metaweb promotes some users to

The underlying data storage supports multilingual data, but as of 2011 every user’s display language was forcibly set to English. This will change at some point.

As of 2011, the only access is via MQL.[10]

Business and community

The Freebase system is built and

In terms of Freebase's relationship with the open data community:

...we have no formal relationship with other open data projects. Though the definition of open data is pretty loose, we try to follow general open data principles by not restricting access to Freebase information to registered users, charging users to access our information, imposing restrictive licenses over the use of Freebase information, or using proprietary or closed technology as a barrier to accessing Freebase information.[13]

Freebase is planning formal mappings of some of their types to established ontologies like FOAF, though this is not a priority.[14]

In the future, the company hopes to also generate profit by organizing proprietary data.[15]


Bulk import tools
They are used internally at Metaweb, but the reconciliation process for imported data has so far proved too complicated for public release, and public bulk tools are very limited.[16]
Multilingual implementation
Freebase has translations (or translation support) of many of its topics, but its types are currently implemented (or at least described) in natural language English, leading to challenges in developing a universal schema.

See also


External links

  • Freebase Blog
  • Freebase Wiki
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