The MetaObject Facility Specification™ (MOF™)is the foundation of OMG's industry-standard environment where models can be exported from one application, imported into another, transported across a network, stored in a repository and then retrieved, rendered into different formats (including XMI™, OMG's XML-based standard format for model transmission and storage), transformed, and used to generate application code.
These functions are not restricted to structural models, or even to models defined in UML - behavioral models and data models also participate in this environment, and non-UML modeling languages can partake also, as long as they are MOF-based. We'll explain what this means in a moment.