An update of XL Fortran V10.1 for Linux provides a fix or multiple fixes to the product. You can download updates from the support web site: http://www.ibm.com/software/awdtools/fortran/xlfortran/support
Every update package comes in tar.gz (or compressed) format and includes a version of the xlf_install utility that is customized to install only the update that accompanies it. If you have any version (including an earlier update) of XL Fortran V10.1 for Linux installed on your system, you can apply the latest update. If you are applying the update to an installation in the default location, follow the procedure in Running the xlf_install utility to update a basic installation. If you are applying the update to an installation in a non-default location, you must use one of the procedures in Installing XL Fortran to a non-default location (for advanced users).