REX Real Estate, a real estate platform that aimed to build a marketplace outside the MLS with operations in 19 states, has joined six MLSs. The company sued NAR and Zillow in March 2021, alleging antitrust violations because of NAR requirements that MLS participants segment listings from MLS sources and non-MLS sources. The implications for this move are not clear now, but is a development to watch as REX has garnered attention inside and outside the industry with its take on the MLS and NAR.