This is the GNU Fortran 95 Runtime library (libgfortran). It is intended to be compiled as part of GCC. Programs must be linked with "-lgfortran -lm". The 'gfortran' driver does this automatically. You'll need to apply gcc_config.patch to your top level GCC source directory. This tells the the GCC configure system about libgfor. This patch can confuse patch as it contains a filename with a '-' in it. use "patch -p1" to avoid this problem. For more information about GNU Fortran 95, see http://gcc-g95.sourceforge.net Paul Brook