HTML isn't a programming language. It isn't Turing complete, and thus can't be used to implement arbitrary algorithms.

It depends on what is you expose to Java or a .NET language. You could use COBOL to marshall your COBOL style data into strings, integers, or whatever else you needed (the Visual COBOL compiler makes this very easy) and those would be just as you expected when read from another language. You can write classes in COBOL that will appear to .NET or Java code like any other managed objects, and use these as an interop layer into existing procedural COBOL.

Most cruft-ridden mainframe apps will recompile without too much major fiddlage, but some things may require tweaking. There's also a managed (.NET only at the moment) version of CICS - see http://www.microfocus.com/aboutmicrofocus/pressroom/releases/pr20100712268224.asp[^]

COBOL is now available to run under .NET or JVM, has proper OO, and you can run your applications on Windows, Linux, Unix or up in the cloud. Oh, and we've demonstrated them running on android phones too. That modern enough for you? See: http://visualcobol.microfocus.com/[^] or http://www.theregister.co.uk/2011/01/20/cobol_update/[^]