Time, and many different iterations of both the language and the hardware, have irrevocably linked COBOL and the mainframe. No matter how both have evolved, COBOL remains the mainstay language of the mainframe. Neither show any sign of declining popularity among those who depend on them most.
Many use Micro Focus Visual COBOL to develop COBOL applications within the Microsoft Visual Studio and Eclipse IDEs. Using the same solution, developers can create COBOL applications that run as .NET-managed code in the .NET environment, and develop and compile applications to native COBOL code, as .exe or .dll before deploying and further debugging the application under COBOL Server, a companion to Visual COBOL. Eclipse plug-ins open the door to other languages, such as Ada, ABAP, C, C++, C#, JavaScript and Ruby.
This IBM tutorial can help write a COBOL program for the z/OS, while this links to a sample Micro Focus COBOL program. These step-through guides explain how to write mainframe programs for Windows and Linux.
The Micro Focus Enterprise suite of mainframe deployment solutions enables comprehensive and flexible analysis, development, and test capabilities for IBM mainframe applications.