How to use Boinc with Fortran and Visual Developer Studio.

Start by creating a new fortran project. Add all the fortran specific files, then
add all the files needed for the boinc library (fx boinc_api.C). Make sure that 
Boinc and the fortran files are compiled using the same type of standard libraries.
ie if the boinc is compiled with the debug multithreaded DLL libraries, make sure the
fortran files are compiled with the DLL setting.

For every boinc function you want to call from fortran you must add an interface and
subroutine:
INTERFACE
  SUBROUTINE boinc_finish(status)	
  END SUBROUTINE boinc_finish
END INTERFACE

Remember to declare the type of arguments.
INTEGER status

You must then tell the compiler that the function you are interfacing is a c routine.
You do this by adding the statement:
 !DEC$ ATTRIBUTES C :: boinc_finish
Because boinc is compiled as C++ files the fortran compiler will not be able to find 
the standard function name in the object file, you therefore have to add an alias for
the function giving the real function name:
 !DEC$ ATTRIBUTES ALIAS : '?boinc_finish@@YAHH@Z' :: boinc__finish
This functionname can be found in the object file.
Go to your compile directory and run dumpbin.

c:\fortranproject\Release>dumpbin /symbols boinc_api.obj

this will give you a list of symbols, where you can find the real functionname.

The interface will end up looking like this:

INTERFACE
  SUBROUTINE boinc_finish(status)
    !DEC$ ATTRIBUTES C :: boinc_finish
    !DEC$ ATTRIBUTES ALIAS : '?boinc_finish@@YAHH@Z' :: boinc__finish
    INTEGER status	
  END SUBROUTINE boinc_finish
END INTERFACE

You can now call the boinc function in fortran.
call boinc_finish(0)