Fortran Filename extension

http://www.ats.ucla.edu/clusters/common/computing/compilers.htm

Fortran 90/Fortran 77 Commands associated with Compilers

Compiler	Serial * fileName extension, not command used, determines language version (can be changed by command flags)			Parallel * See the MPI doc.
	Commands	Fortran 90 fileName extensions	Fixed Format fileName extensions	Fortran 90	Fortran 77
Intel	ifort	.f90 (.F90 preprocessed)	.f, .for, .ftn (.F, .FOR, .FTN, .FPP preprocessed)	mpif90	mpf77
GNU	gfortran	.f90 (.F90 preprocessed)	.f, .for, .ftn

http://software.intel.com/sites/products/documentation/hpc/compilerpro/en-us/fortran/lin/compiler_f/bldaps_for/common/bldaps_under_inpext.htm

Filename	Interpretation	Action
filename.f filename.for filename.ftn filename.i	Fortran fixed-form source	Compiled by the Intel® Fortran compiler.
filename.fpp and, on Linux, filenames with the following uppercase extensions: .FPP, .F,.FOR, .FTN	Fortran fixed-form source	Automatically preprocessed by the Intel Fortran preprocessor fpp; then compiled by the Intel Fortran compiler.
filename.f90 filename.i90	Fortran free-form source	Compiled by the Intel Fortran compiler.
filename.F90 (Linux OS and Mac OS X)	Fortran free-form source	Automatically preprocessed by the Intel Fortran preprocessor fpp; then compiled by the Intel Fortran compiler.

http://help.eclipse.org/indigo/index.jsp?topic=%2Forg.eclipse.photran.doc.user%2Fhtml%2Fbasic%2FWritingCode.html

Filename Extensions	Source Form/Preprocessing
.f, .fix, .for, .fpp, .ftn .F, .F77, .FIX, .FOR, .FTN, .FPP, .fpp	Fixed source form
.f08, .f03, .f95, .f90	Free source form with INCLUDE lines
.F08, .F03, .F95, .F90	Free source form with C preprocessor directives