Hi Tom, > /usr/lib64/gcc/x86_64-suse-linux/4.3/libstdc++.so: undefined reference > to [log in to unmask] that is a known issue with using a g95 based on GCC 4.0 with a later GCC. The work around is a bit of a hack. Look for the file "libgcc_s.so.1" in your g95 distribution and replace that with a softlink to the current version, usually in /lib, i.e.: % mv libgcc_s.so.1 libgcc_s.so.1.ori % ln -s /lib/libgcc_s.so.1 libgcc_s.so.1 and then just restart "make world". Peter.