Which Intel Fortran compiler package did you install?

Xcode must be installed first, followed by installing the Intel compiler.

If the Intel Fortran integrations with Xcode installed successfully, there will be a Default Fortran rule defined under the Rules tab for the Target. Using the Xcode GUI, under Groups & Files, right-click the target name, then left-click Get Info and finally click on the Rules tab. Scroll through the rules to see if a Default Fortran rule exists.

If you do not see a Default Fortran rule then there may have been an issue installing the Intel Fortran Xcode integrations. If the rule is missing, first make certain you are only installing the Intel Fortran 10.1 Release with Xcode 3.0, uninstall the current Intel Fortran compiler and then re-install it.

Regarding the makefile issue, what was the error you received when running the makefile when trying to use ifort?

The enclosed makefile is configured to use xlf90, but perhaps the version you ran with ifort contains FC=ifort and the appropriate FFLAGS settings for ifort specific options.

While it is not necessary, you can also "source" the ifort setup script ifortvars.sh or ifortvars.csh to initialize your working shell to use the ifort compiler. The ifort setup scripts reside in the Intel Fortran compiler installation directory under the parent directory /opt/intel.