Migrating from Fortran to Fortran with the NAGWare f and f Tools

The investment in code written in the Fortran language over the last four decades means that there is a vast amount of legacy code written to various standards and incorporating numerous vendor extensions to the language Meanwhile the new For tran standard adds many attractive new features to the language while retaining compatibility with Fortran This paper shows how the NAGWare f Tools may be used to standardise Fortran code to a form suitable for porting to standard con forming Fortran compilers Then the paper goes on to discuss how the NAGWare f Tools can be used to convert this code to free format Fortran with standardised precision