On Aug 15, 2012, at 5:28 AM, Berend Hasselman <bhh at xs4all.nl> wrote: > To be completely sure: for ML I only have to install gfortran-lion-5666-3.pkg (from r.research.att.com) and Xcode + CLI tools? No, the "regular" Fortran from the top of the page or from CRAN - there is no Xcode add-on. Cheers, Simon