1. A method of creating models of alternative physical representations of one or more entities, each alternative physical representation corresponding to a wire format, the alternative physical representations facilitating conversions from one wire format to another, the method comprising: creating a meta-model for defining entity models, the meta-model including a logical meta-model and a physical meta-model, the logical meta-model defining a logical model describing a logical structure of the one or more entities in a platform and programming language neutral manner wherein said logical meta-model comprises logical entity component classes representing logical entity components, and the physical meta-model defining a physical model describing a plurality of alternative physical representations of the one or more entities whose logical structure is described in the logical model, said physical meta-model comprising base classes which represent wire format neutral physical entity components corresponding to said logical entity components, and further comprising correspondence associations between said logical entity component classes and said corresponding base classes wherein said physical meta-model comprises a mapper class for representing said correspondence associations, said mapper class having a first association with a logical entity component class and a second association with a corresponding base class; and creating the plurality of alternative physical representations.
2. The method of claim 1 wherein the one or more entities are messages.