[/quote]http://www.gnustep.org/ implements OpenStep on which Cocoa is based. (However it usually requires recompilation, and several OS X API's such as spotlight, etc is missing) More background: http://en.wikipedia.org/wiki/GNUstep http://en.wikipedia.org/wiki/Cocoa_(API) Gert[/quote] I don`t think , that GNUstep makes it possible to run MacOS X app`s ,the same way WINE does with Windows .exe files , which is what I asked. And how hard would be to do , let`s say McWINE branch of WINE, that can do that ?