The Darling Project is still in its infancy and only works to currently let some basic OS X programs run on Linux. Darling relies upon GNUstep and other code-bases while having very ambitious aims of having binary support for OS X programs on Linux.
Phoronix reader "Pedro" wrote in to share that he's seen the project restarted after months without any activity. The Darling project site is now fresh and has been launched at DarlingHQ.org. There's also new commits in this Git repository. Recent Git work on Darling includes regression fixes and other small changes; activity just started back up this week for what's going to the mainline GitHub code-base.
Are there any Apple programs you would want to run in this OS X translation layer to Linux? For those wanting to help out, Luboš Doležel recommends picking a framework or set of APIs to focus on implementing. The lead developer has lately been working on CoreAudio support and getting the mpg123 program working with CoreAudio on Darling. The developer says in the mailing list he's been busy with family commitments that takes him away from Darling and that he's writing his master's thesis on Darling.