For applications or middlewares and systems and utilities? For applications, COBOL is king, closely followed by Java for stuff that needs web interfaces. For m

For applications or middlewares and systems and utilities? For applications, COBOL is king, closely followed by Java for stuff that needs web interfaces. For middleware and systems and utilities etc, assembly, C, C++, REXX, Shell, and probably there is still some PL/X going on too but I'm not sure. You'd have to ask somebody working on the products (like Db2) that famously used PL/X. I'm pretty sure a public compiler was never released for PL/X so only IBM and possibly Broadcom have access to use it. COBOL is best thought of as a domain specific language. It's great at what it does, but the use cases are limited you would be crazy to write an OS in it.