Arizona Regional Multiple Listing Service (ARMLS®) is the largest MLS in Arizona, providing MLS and other core services for MLS subscribers. ARMLS® began operations in 1982 through collaboration by the shareholder boards to form the first regional MLS in the country. Now 30 years later, ARMLS® provides training, support, and technology solutions for 39,000 real estate agents. ARMLS® contracts not only with MLS search vendors but also engages other key service providers for mapping, lockbox services, remote MLS access through mobile devices, listing syndication and statistical data analysis. ARMLS® invests heavily in technology, including their own in-house tax system called Monsoon.