I think it's important to note that this isn't an option to "get off the mainframe". Gnu Cobol doesn't support CICS, nor some other things the mainframe provide

I think it's important to note that this isn't an option to "get off the mainframe". Gnu Cobol doesn't support CICS, nor some other things the mainframe provides. There are "rehosting" options, both free and for pay, this isn't one. To clarify some more, rehosting options range from "pick up and drop source files and data to the new system" to "we can do it but it's almost as much effort as rewriting the whole thing".