Meta Content Framework
Meta Content Framework (MCF) is a specification of a content format for structuring metadata about web sites and other data.
History
[edit]MCF was developed by Ramanathan V. Guha at Apple Computer's Advanced Technology Group between 1995 and 1997. Rooted in knowledge-representation systems such as CycL, KRL, and KIF, it sought to describe objects, their attributes, and the relationships between them.[1]
One application of MCF was HotSauce, also developed by Guha while at Apple. It generated a 3D visualization of a web site's table of contents, based on MCF descriptions. By late 1996, a few hundred sites were creating MCF files and Apple HotSauce allowed users to browse these MCF representations in 3D.[1]
When the research project was discontinued, Guha left Apple for Netscape, where, in collaboration with Tim Bray, he adapted MCF to use XML[2][3] and created the first version of the Resource Description Framework (RDF).[4]
MCF format
[edit]An MCF file consists of one or more blocks, each corresponding to an entity. A block looks like this:
Node: <identifier>
<property>: <value>, <value>
The identifier is a unique identifier for that entity (more on the scope of the identifier below) and is used to refer to that entity. The following lines each specify a property and one or more values, separated by commas. Each value can be a reference to another entity (via its identifier), a string (enclosed by double quotes) or a number. For example:
Node: Test1
typeOf: TestNode
child: Test2, Test3
name: "I am a test node"
itemCode: 42
Node: Test2
typeOf: TestNode
sibling: Test3
name: "I am another test node in a test world"
Node: Test3
typeOf: TestNode
sibling: Test2
name: "Just another test node in a test world"
NOTE:
- The identifier must not include a comma (
,
) and must not be enclosed within double quotes. - A common parsing failure is due to odd number of unescaped double quotes in text. For instance,
"foo bar" baz"
needs to be"foo bar\" baz"
. - Commas within double quotes are not considered as value separators.
- Every entity has at least one property:
typeOf
.
References
[edit]- ^ a b Hammersley, Ben (2003). Content Syndication with RSS. Sebastopol: O'Reilly. p. 2. ISBN 978-0-596-00383-8.
- ^ Guha, R V; Tim Bray (1997-06-06). Meta Content Framework Using XML. W3C. Retrieved 2014-09-14.
- ^ Guha, R.V.; Bray, Tim (1997-06-13). "Meta Content Framework Using XML". Netscape. Archived from the original on June 15, 1997. Retrieved 2015-12-12.
- ^ Andreessen, Marc (1999-01-08). "Innovators of the Net: R.V. Guha and RDF". Netscape. Archived from the original on February 5, 2008. Retrieved 2014-09-14.
External links
[edit]- MCF Tutorial (using XML syntax)
- Guha MCF site
- The metacontent concept