Metropolitan Regional Information Systems

MRIS operates two parallel systems available only to licensed brokers, agents, and others (such as appraisers): "MATRIX" which is the database of property listings in all classes (including residential to raw land and lots) and categories from "Active" through "Sold" going back over more than ten years; and "KEYSTONE" the data entry site for agents to input new listings and update them. On a daily basis, portions of the data from the full MRIS database of real estate listings is uploaded to public-access websites such as Realtor.com (with over 1 million listings nationwide) or to MRIS' own public-access site, http://homesdatabase.com, with the majority of the organization's members Washington DC area properties. ==Member organizations==

Originally, brokers and agents doing business in different jurisdictions would have been required to obtain membership in several different MLS systems. When joining an individual Association of Realtors and becoming affiliated with NAR at the same time, individual brokers and agents have the option of joining MRIS. However, it would be difficult to conduct business without having access to the MLS system. ==Legal==

In 2012, The MRIS was hit with an antitrust lawsuit by the American Home Realty Network, alleging that MRIS and NorthStar MLS were concerting an anti-competitive group boycott of American Home Realty Network. The lawsuit alleged that MRIS's lawsuit against American Home Realty Network and Northstar MLS's lawsuit against American Home Realty Network in Minnesota were attempts to drive American Home Realty Network out of business and eliminate it as a competitor in the market for real estate broker services. ==See also==