MLS Swift must be installed in a Windows environment in order to send listing data to the listing services. If you have an Apple Macintosh produced after August 2007, you may use the Crossover software from www.codeweavers.com to provide the needed environment. MLS Swift is tested in this environment and has been found to have satisfactory performance. Trial versions of Crossover are fully functional for two weeks, to allow you to determine that you are satisfied before purchasing it.