I've written a command line application in XCode using Objective-C. When added to my /usr/local/bin path is works as expected in OS X. However, I would like to make the binary work on Linux.
The binary relies on an Objective-C framework. How would I go about doing this? Or is it even possible?
Yes, it should be possible by installing GNUstep: http://www.gnustep.org/
The basics of Objective-C are supported by the GNU compiler collection. In order to utilize the full power of Objective-C together with the Cocoa /openStep environments on Linux, and to work with many of the examples covered in this book, it is necessary to install gcc, the gcc Objective-C support package and the GNUstep environment.
The gcc Objective-C support can be installed on Linux simply by installing the gcc-objc package which is available with all Linux distributions. There are, however, two different paths to installing GNUstep. On those Linux distributions for which pre-built GNUstep packages are provided this is simply a matter of issuing the appropriate command to install GNUstep. On Linux distributions for which pre-built packages are not available, the process involves downloading the GNUstep source code and then building and installing the packages manually.
Take a look at this article explaining this step by (gnu)step :) http://www.techotopia.com/index.php/Installing_and_Using_GNUstep_and_Objective-C_on_Linux