The Darling project is beginning to see new activity on GitHub after months of dormancy and the website has moved to a new address DarlingHQ.org.
Similar to how Wine allows Windows applications to run on Linux OS the Darling project is trying to build a software compatibility layer to run OS X apps.
The Darling translation layer can currently run a number of OS X console tools and applications, such as Midnight Commander, and some simple GUI applications with the help of the GNUstep project.