OpenCyc is the open source version of the Cyc(r) knowledge base (artificial intelligence).
Our new XML schema for knowledge serialization has passed the W3C XML schema validator at http://www.w3.org/2001/03/webdata/xsv
Developers can use CycML to exchange knowledge with one another, and CycML will also allow the KB contents to be imported and exported for archiving. The schema definition allows validating XML parsers to check the compliance of CycML with our published schema, regarding the nesting of the defined elements and their attributes. The OpenCyc inference engine ensures that imported CycML assertions are well formed according to the semantic constraints of the contained relationships and concept types.
The CycML schema is located at http://opencyc.sourceforge.net/cycml.xsd and an example instance is located at http://opencyc.sourceforge.net/example-05-cycml.xml
Schema validating with XSV 1.190/1.95 of 2001/05/07 08:38:12
(Real name: http://opencyc.sourceforge.net/example-05-cycml.xml
Length: 3313 bytes
Last Modified: Tue, 29 May 2001 21:46:58 GMT
Server: Apache/1.3.19 (Unix) PHP/4.0.5)
No declaration for document root found, validation was lax
The schema(s) used for schema-validation had no errors
No schema-validity problems were found in the target