The Meta-Messager aims to provide a generic framework and toolset for semantic annotation of business message schemas and semantic reconciliation of business messages using reference business ontologies, irrespectively of standards used to specify or represent the messages. The framework is built up on a Message Metamodel that is a generic intermediate form for representing message schemas and message instances of different message-representation syntaxes (such as XML, EDI, ASN.1, or STEP Part21).
Many industry projects involve content validation and mapping and transformation of messages used in manufacturing supply chains and other applications. Those projects may involve different message formats: XML  as defined by XML Schemas , RDF XML , UN/EDIFACT , North American EDI , or the STEP Clear Text Exchange form [6, 7]. A neutral form for representing messages of all these syntactic varieties would be a useful intermediate step in the development of message content validation or mapping software. The neutral form insulates the validation and conversion activities from the message syntax, and allows the content testing and semantic mapping software to be reused with different physical representation syntaxes. The neutral form is defined by the NIST Message Metamodel.
Separating the exchange syntax and schemas from the validation and conversion routines also ensures that they all can use the same message parsing and generation services for any given specific syntax. And it necessitates the construction of software libraries to convert schema and message content to and from the NIST Message Metamodel (MMM) form.
NIST Message Metamodel captures concepts from particular message schema or message instance, or from both. Hence, the Message Metamodel consists of two logical parts