| Environmental variable | Directory | Purpose |
| HPF | ~/Fortran | Code-related files |
| HPF_SRC, HPF_src | $HPF/src, $HPF/src/temp | For final and development source codes (make subdirectories when needed) |
| HPF_EXE, HPF_exe | $HPF/exe, $HPF/exe/temp | For executables, in $path. |
| HPF_LINK, HPF_link | $HPF/link, $HPF/link/temp | For object files (like from module compilation) |
| HPF_LIBS | $HPF/libs | The most important directory--not to be touched. It contains the shared and static libraries to be linked. In $LD_LIBRARY_PATH. |
| HPF_MODULES, HPF_modules | $HPF/modules, HPF/modules/temp | For module .mod files. |
| HPF_TMP | $HPF/tmp | Development scratch work. |
| HPF_PROF | $HPF/profiles | For profiling and debugging files |
| HPF_GRAPHS | ~/Graphics | For graphic images |