There&#x27;s also some practical reasons for keeping a program on the mainframe. I currently work in mainframe development at a large company. We&#x27;re in the beginning stages of &quot;modernizing&quot; some of our mainframe applications (moving the user interface from CICS to the web). The main workhorse processes will still be on the mainframe, and for good reason: it&#x27;s a goddamn powerhouse. Should we get a high volumes, we can give the processes some extra CPU&#x27;s and MIPS, and it&#x27;ll chug along even faster. It&#x27;s a bit more difficult to provision extra VMs for a distributed server environment in order to do such things.<p>Plus, for all of COBOL&#x27;s faults, it&#x27;s simply more efficient for &quot;business-y&quot; processes. All anyone cares about is manipulating data found within a file or database, and that&#x27;s what COBOL excels at.