
Installing a precompiled, up-to-date binary from HPC Mac OS X (GCC 4.2.1 is the latest Apple compiler it was released in 2007.) Installs to /usr/bin. Disadvantages: Compiler stack will be really old.Advantages: Matches versions of compilers installed with XCode or with Kenneth Reitz's installer unlikely to interfere with OS upgrades coexists nicely with MacPorts (and probably Fink and Homebrew) because it installs to /usr/bin.The R developers and SciPy developers recommend this method. installed on your machine, download the appropriate version of gfortran from here.

If you want the version of gfortran to match the versions of gcc, g++, etc. Installing a version that matches system compilers


In the two years since, Homebrew has grown a lot as a project and has proved more maintainable than MacPorts, which can require a lot of PATH hacking. Originally, I preferred MacPorts when I wrote this answer. I have tried all of these methods except for "Fink" and "Other Methods".
