Dave, I'm not sure I understand the question, though I am sure your customer phrased it that way.
Intel Visual Fortran evolved from Compaq Visual Fortran. The compiler is derived from Compaq Visual Fortran and retains all of the Fortran language features from CVF.
Intel Visual Fortran includes a complete Fortran development environment, as did CVF, but now based on Microsoft Visual Studio 2010 rather than Visual Studio 98. It will work with a Visual Studio 2005, 2008 or 2010 that the customer already has installed as well. If a separately installed Visual Studio is present, CVF projects can be converted to Intel Visual Fortran projects automatically. This conversion is not available using the bundled Visual Studio 2010 Shell, however.
Most of our customers moving from CVF have found that a simple rebuild is all they need, though Intel Fortran may diagnose some coding errors missed by CVF, and any third-party Fortran libraries used will need to rebuilt with the Intel compiler. Please read and/or direct your customer to read
Migrating from Compaq Visual Fortran, which should answer many of your customer's questions. You or your customer should feel free to ask additional questions if you have them.
