Editing Meta-Object Facility (section)

== Overview ==
MOF was developed to provide a [[type system]] for use in the [[CORBA]] architecture, a set of schemas by which the structure, meaning and behaviour of objects could be defined, and a set of CORBA interfaces through which these schemas could be created, stored and manipulated.<ref>{{cite web|title=Common Facilities RFP-5: Meta-Object Facility|url=http://www.omg.org/cgi-bin/doc?cf/96-05-02.pdf|publisher=Object Management Group|access-date=14 January 2014|date=2 May 1996}}</ref> 

MOF is designed as a four-layered architecture. It provides a meta-meta model at the top layer, called the M3 layer. This M3-model is the language used by MOF to build metamodels, called M2-models. The most prominent example of a Layer 2 MOF model is the UML metamodel, the model that describes the UML itself. These M2-models describe elements of the M1-layer, and thus M1-models. These would be, for example, models written in UML. The last layer is the M0-layer or data layer. It is used to describe real-world objects.

Beyond the M3-model, MOF describes the means to create and manipulate models and metamodels by defining [[CORBA]] interfaces that describe those operations. Because of the similarities between the MOF M3-model and UML structure models, MOF metamodels are usually modeled as UML class diagrams. 

=== File formats ===
A conversion from MOF specification models (M3-, M2-, or M1-Layer) to W3C XML and XSD are specified by the [[XML Metadata Interchange|XMI]] (ISO/IEC 19503) specification. XMI is an XML-based exchange format for models.{{r|mof241|page=xi}}

From MOF to Java™ there is the Java Metadata Interchange (JMI) specification by [[Java Community Process]].{{r|mof241|page=xi}}

It also provides specs to make easier automatic CORBA IDL interfaces generation.{{r|mof241|page=3}}