Experiments aren't usually written in FORTRAN.

The programmer is by far the slowest part of HPC. It often makes sense to use the language you're fastest at instead of the language that will run the fastest.

It's very common for experiments to be written in languages not know for their performance (Java, Matlab, Perl, and Python for instance).

For reference, here are some of the packages commonly used in experiments[1]:

    BLAS        Fortran                 http://www.netlib.org/blas/#_software
    NCBI BLAST  C++                     ftp://ftp.ncbi.nlm.nih.gov/blast/executables/blast+/LATEST/ncbi-blast-2.2.30+-src.zip
    BFAST       C                       http://sourceforge.net/projects/bfast/
    BioPerl     Perl                    https://github.com/bioperl/bioperl-live
    Bowtie      C++, C                  http://sourceforge.net/projects/bowtie-bio/files/bowtie/
    Clustal     C, C++                  http://www.clustal.org/omega/#Download
    cp2k        Fortran                 https://github.com/cp2k/cp2k
    Gromacs     C                       https://github.com/gromacs/gromacs
    HTSeq       Python                  https://pypi.python.org/pypi/HTSeq
    MUSCLE      C++                     http://www.drive5.com/muscle/downloads.htm
    MrBayes     C                       http://sourceforge.net/p/mrbayes/code/HEAD/tree/
    OpenFOAM    C++                     https://github.com/OpenFOAM/OpenFOAM-2.3.x
    SAMtools    C                       https://github.com/samtools/samtools
    SNAP        C                       http://korflab.ucdavis.edu/software.html
    fftw3       C                       https://github.com/FFTW/fftw3

[1]: I went down this list and picked some of the ones I remember using (been out of the HPC world for a couple years): https://portal.tacc.utexas.edu/software It'll be a bit skewed towards genomics.