MDDL (Market Data Definition Language) is an XML-based messaging format for exchanging information related to
Financial Instruments Corporate events related to the financial instruments Market-related data MDDL was developed by FISD (Financial Information Services Division) of SIIA (Software & Information Industry Association). The initiative for the use of XML in market data exchange was started in 2000 and has been gaining industry-wide acceptance.
External links archived MDDL web site (9-2-2014) The Book: MDDL and the Quest for a Market Data Standard Metatrader VPS