ISO/IEC JTC1/SC22/WG5 N1605 DTR ISO/IEC TR 19767 - Enhanced Module Facilities in Fortran Abstract Fortran is a computer language for scientific and technical programming that is tailored for efficient run-time execution on a wide variety of processors. The module facility of Fortran is useful for structuring Fortran programs because it allows related procedures, data, and types to be collected into a single coherent program unit. This facility, as provided in Fortran 95 (International Standard 1539-1:1997) and Fortran 2003 (the forthcoming revision), is adequate for small and moderate-size programs, but has deficiencies for large programs or programs with large modules. Technical Report 19767 addresses these deficiencies by allowing a module to be divided into an "interface" part and one or more "implementation" parts. This facilitates separate development of the implementation parts, and reduces maintenance costs by clearly delineating other dependencies therein. The compilation of program units that use a module depends only on its interface part, so this is not affected by the development and maintenance of the implementation parts of the module. This also provides benefits for packaging and publishing proprietary software since the interface part may be published openly while the implementation parts remain proprietary. The provisions in Technical Report 19767 are posed as an amendment to Fortran 2003, and are compatible with it. Although the provisions are not posed as an amendment to Fortran 95, they are also compatible with that version.