Pat,
It sounds like the IT department has blinders on or they are suffering form rectal-cranial inversion.

The question should not be : What platform the app was developed on? It should be : Does the app work? If the app performs all necessary functions and has the appropriate bells and whistles, then it should be used. If the IT gurus wish to commission an app using SQL server then offer to do. Meanwhile your Fox app can be used by those who need to get the job done.