Known users from DebianScience listed in parenthesis.
Fortran tools for science already packaged in Debian
g77 (Rick Bahague, Enrico Zini)
gfortran (Enrico Zini)
Fortran tools for science that could be considered for inclusion in Debian
arprec (Christophe Prud'homme) Christophe is working on its debian package.
fortranposix upstream packaged by Kamaraju S Kusumanchi
gnuplotfortran upstream packaged by Kamaraju S Kusumanchi
www.open64.net has a openf95 compiler, there's some stuff started on it at http://gnu.ethz.ch/debian/open64/