For sure there&#x27;s still software written for the IBM 360&#x2F;370 mainframe series in production, just running either natively or in emulation on a newer zSeries &#x27;frame. &quot;Mainframe&quot; doesn&#x27;t necessarily mean &quot;old&quot;.<p>I used to run a couple hobbyist&#x2F;enthusiast sites and mailing lists for people who collected and restored old DEC equipment (and I still run an all-systems-welcome &quot;rescue&quot; list).  Shortly after 9&#x2F;11, I got a phone call from someone working in the Pentagon who was looking for parts to repair a VAX that had been damaged...