IBM: XMI, the XML Metadata Interchange Format

[This local archive copy mirrored from the canonical site: http://www.software.ibm.com/ad/features/xmi.html; links may not have complete integrity, so use the canonical document at this URL if possible.]

<XMI> "XML Metadata Interchange" </XMI>

An OMG SMIF Proposal

If you've been following the industry's efforts to enhance the exchange of information on the web, then you're probably already familiar with the Extensible Markup Language (XML). XML is an open standard of the World Wide Web Consortium (W3C) designed as a data format for structured document interchange on the web. It extends your tagging options by allowing you to define your own metadata when HTML is not a good fit.

Now, IBM, Unisys, and other industry leaders are proposing a new open industry standard that would combine the benefits of the web-based XML standard for defining, validating, and sharing document formats on the web with the benefits of the object-oriented Unified Markup Language (UML), a specification of the Object Management Group (OMG) that provides application developers a common language for specifying, visualizing, constructing, and documenting distributed objects and business models.

The XML Metadata Interchange Format (XMI) specifies an open information interchange model that is intended to give developers working with object technology the ability to exchange programming data over the Internet in a standardized way, thus bringing consistency and compatibility to applications created in collaborative environments. By establishing an industry standard for storing and sharing object programming information, development teams using various tools from multiple vendors can still collaborate on applications. The proposed standard will allow developers to leverage the web to exchange data between tools, applications, and repositories to create secure, distributed applications built in a team development environment.

What are the objectives of XMI?

To allow the exchange of objects from the OMG's Object Analysis and Design Facility. These objects are more commonly described as UML (Unified Modeling Language) and MOF (Meta Objects Facility). Currently there is no agreed industry standard way of doing this, which can lead to a variety of proprietary formats, each specific to a vendor tool. Also, XMI is intended to be a "stream" format. That is, it can either be stored in a traditional file system or streamed across the Internet from a database or repository.

What is the current status of XMI?

XMI was developed as a response to the OMG's request for proposals for a stream-based model interchange format (the SMIF RFP). The XMI proposal was outlined at the June 98 OMG technical committee meeting in Orlando, where XMI was identified as the cornerstone of open information model interchange. A detailed submission will be made at the July 98 OMG meeting in Helskinki. The plan is to follow the policies and procedures of the OMG to result in the adoption of XMI as an open standard in March 99.

Who is behind XMI?

XMI was originally sponsored by IBM and Unisys as a result of their joint work from last year on the OMG UML and MOF standards. Oracle, DSTC, and Platinum Technology are co-submitters of the proposal. Other supporters include SELECT Software Tools, Rational Software, Inline Software, and Sybase.

What does XMI cover?

The initial proposal covers the transfer of UML models and MOF meta models. It identifies standard XML DTD's to allow the exchange of UML and MOF information. Follow on proposals may cover additional domains such as datawarehousing, component-based development, and web metadata. XMI will also enable the automatic generation of XML DTDs for each meta information model.