The financial industry has long been a focus for daily activity of all walks of life. From periodicals to news bulletins, the media promotes the performance and specifics of the stock markets to billions globally. Individuals are increasingly more active in monitoring "the market" enabling them to contribute directly to portfolio investment decisions previously handled only by professionals.

Under the auspices of the FISD of the SIIA, MDDL has been developed by an industry-wide consortium including the largest players in the financial market for the distribution and interchange, via XML, of the financial data that comprise the basis for this activity. Launched on 02 November 2001, the specification initially covers snapshot quotes and data fields for instruments like equities and indices but the framework is developing to include all types of financial instruments and related data. MDDL seeks to provide a common vocabulary and common data model definitions to facilitate the interchange of market data from source through vendors to the end-users OR consumers.

Market data is often delivered on dedicated circuits using highly specific compression schemes involving a large base refresh or "snapshot" of the data followed by subsequent smaller streaming