This free service, offered by Polyhedron Solutions, allows you to submit your Fortran 77 source code (up to 100 lines), and to view the result of processing it using SPAG – part of Polyhedron’s plusFORT toolset.
A very small subset of the customization options available in the full plusFORT package is available using the drop-down boxes.
Paste your code into the F77 code window, choose your conversion
options and press SUBMIT. The converted code will appear in the F90 code window and a log
of the conversion process can be viewed by pressing the ‘show output log’ button.