Similar to how Wine allows Windows applications to run in Linux OS, the Darling project is trying to build a software compatibility layer to run OS X apps. Linux challengers
So far the project has a small number of OS X programs working with Darling and is testing various other applications, such as Midnight Commander, QREncoder, Bayon, The Unarchiver and World of Warcraft. Which apps could or couldn’t be run on the Darling layer isn’t yet clear.