Since Xojo added support for Windows (1999) and Linux (2005), you have been able to cross-compile for those platforms on a Mac. The reverse, building for macOS from Windows and Linux, was true for many years and then things changed in 2020. I’m happy to report that the Xojo engineers have overcome the hurdles that prevented building for macOS from Windows and Linux. The ability to cross-compile macOS apps from Windows and Linux will return in Xojo 2021r3. If you have an active Xojo license, I encourage you to go to the Testers channel on the forum and try it out. We’d appreciate any feedback you have (positive or negative). If you don’t have an active license but would still like to help test Xojo, we can help make that happen.