Dear Prof O, I installed your 20070904 version of GPC on my Red Hat Linux machine. When I run gpc I get the following error, which I believe indicates that my operating system needs to be updated. [hashemi@brndcdf hashemi]$ cd /pascal/bin [hashemi@brndcdf bin]$ ls binobj gpc gpc-run gpidump [hashemi@brndcdf bin]$ ./gpc ./gpc: /lib/libc.so.6: version `GLIBC_2.4' not found (required by ./gpc) ./gpc: /lib/libc.so.6: version `GLIBC_2.3.4' not found (required by ./gpc) [hashemi@brndcdf bin]$ strings /lib/libc.so.6 | grep GLIBC GLIBC_2.0 GLIBC_2.1 GLIBC_2.1.1 GLIBC_2.1.2 GLIBC_2.1.3 GLIBC_2.2 GLIBC_2.2.1 GLIBC_2.2.2 GLIBC_2.2.3 GLIBC_2.2.4 GLIBC_2.2.6 GLIBC_2.3 GLIBC_2.3.2 GLIBC_2.3.3 GLIBC_PRIVATE The GPC version you compiled for me seems to include GCC 4.1.2. Does that sound right? Am I correct in thinking that my system is too old for the new GPC? Yours, Kevan -- Kevan Hashemi, Electrical Engineer Physics Department, Brandeis University http://alignment.hep.brandeis.edu/