Programming accomodating multi-languages and OS

Hi All,

I am new to these forms. I have had experience in coding one language(COBOL on DEC VAX; VB6 on Windows) and one OS. I would like to know how would you approach designing an application that requires development in multiple languages, bridging multiple operating systems, and using multiple programming languages?

Thank you,
C.

I would start by figuring out the requirements.