Scalable Multicore Code for RNA Secondary Structure Prediction
From this post: If you have Xcode 4.3 or newer the command line tools, such as make, are not installed by default. In Xcode preferences go to the "Downloads" tab and under "Components" push the "Install" button next to "Command Line Tools". After you have successfully downloaded and installed the command line tools you should also type the following command in the Terminal to make sure all your Xcode command line tools are switched to use the 4.3 versions:
Installing a C/C++ compiler
The easiest way to install a C/C++ compiler, and take care of the OpenMP dependency, is to install GCC version 4.7 or higher.
Detailed instructions for installing gcc are found here.
OpenMP is included in gcc versions 4.7 and higher. See "Installing a C/C++ compiler" for details of installing gcc.