If you are using ABAQUS on a Linux computer then you might not know that you don't need to purchase the Portland Group's Fortran Compiler (pgf) to use Fortran subroutines, but that you infact can use the Gnu Fortran Compiler g77 which is a free open source compiler.

In order to use the g77 compiler all you need to do is to modify your abaqus_v6.env file to use the following lines:

compile_fortran = ( "g77 -c -O -DLINUX -I%I" )

compile_cpp = ( "g++ -c -fPIC -DPIC -w -Wmissing-prototypes -Wuninitialized " +
"-DHKS_LINUX -DLINUX -DHAS_BOOL -DFOR_TRAIL -DHKS_DEBUG " +
"-D_BSD_TYPES -D_BSD_SOURCE -D_GNU_SOURCE " +
"-D_XOPEN_SOURCE_EXTENDED -DEMULATE_EXCEPTIONS=0 " +
"-DGL_GLEXT_PROTOTYPES -DHAVE_OPENGL -DHKS_OPEN_GL " +
"-DSUN_OGL_NO_VERTEX_MACROS -Winline -fpermissive " +
"-instances=explicit -fexceptions -fstrict-prototype " +
"-fvtable-thunks -DTYPENAME= -D_POSIX_SOURCE " +
"-D_XOPEN_SOURCE -DSPECIALIZE -O0 -I%I" )

link_sl = ( "g++ -Wl,-warn-once -fPIC -fexceptions -fvtable-thunks " +
" -Wl,-export-dynamic -shared %E -Wl,-soname,%U -o %U %F " +
"%A %B -Wl,-Bdynamic -lgcc -lg2c -lm -lc" )

link_exe = ( "g++ -Wl,-warn-once -fexceptions -fPIC -Wl,--no-demangle " +
"-Wl,-noinhibit-exec -o %J %F %M %L %B %O " +
"-lm -lpgc -lgcc -lg2c -lgcc -lg2c" )