Emulating Linux binaries under Mac OS X

Well there is a project introducing something like Linux's binfmt_misc to OS X so now what you need is an ELF loader, a dynamic linker that can load both Mach-O and ELF, and some mechanism to translate Linux calls to OS X ones.

Just for inspiration, you can implement the dynamic linker in the fashion that it ignores filename extension - both libfoo.so.1 (as an Linux ELF) and libfoo.1.dylib (as an Mach-O) can be loaded so that OS X versions of system libraries can be reused so that you do not need to write a "hosted on OS X" libc.so and syscalls can be handled by an kext that translates Linux calls to OS X ones in kernel.

Or, in an more elegant way, implement a stripped down Linux kernel as a kext that makes the OS X kernel a dual-purpose. However that will require you to use two sets of libraries. (Binaries do not clash so it is largely okay)

Set up a virtual machine (I personally use VMWare Fusion) and then install whatever distro of Linux you desire on the virtual machine.

Or, if you have the source to the Linux program, chances are you can recompile it on a Mac and run it natively. If you install Fink or MacPorts, you can install a lot of open source programs without much trouble.

I recently found Noah, which you can use to run Linux binaries on macOS. You can install Noah via homebrew (brew install linux-noah/noah/noah). Then you should be able to do this:

noah linux_binary

In my experience the behavior of the binary matches what I see on my Ubuntu machine.