You will need a fortran compiler, either gfortran or g77.

For Apple OSX, the people from R (http://r.research.att.com/tools/) distribute a package of gfortran for OSX. You need developer command line tools installed. If you are lucky you can find a stripped down package as you only need basic tools and dynamic libraries (e.g.libgfortran.dylib , libgcc_s.dylib). If you are unlucky you have to download some 2-4 GByte from Apple to use < 10 MB of tools/libraries. g77 is no longer included in gcc (>3.4).
For Gnu/Linux use gfortran provided from your distribution.
For Microsoft operation systems Cygwin provides a working gfortran or g77. Have a look at http://gcc.gnu.org/wiki/GFortranBinaries

To build and install from source:


For OSX:
1) Unpack the archive

2) Edit Makefile and choose your compiler by un/commenting the appropriate line and read the warning
e.g.
#COMP = g77
COMP = gfortran -std=legacy

3) To compile all programs type:
$ make

4) Install all binaries in /usr/local/bin:
$ sudo make install

IF you have installed the gfortran provided from the link above, no need to worry any further.
Otherwise /usr/local/bin has to exist. To create it type:
$ sudo mkdir -p /usr/local/bin

/usr/local/bin has to be in your $PATH variable. If it isn't, modify your .profile file:
$ echo "export PATH=/usr/local/bin:$PATH" >> ~/.profile

For users of gfortran, using the option -std=legacy is necessary.
