&quot;z&quot; is the marketing term for all of IBM&#x27;s mainframe products.  There are several different operating systems that can run on the mainframes.<p>This port only applies to those running Linux on their mainframe, which isn&#x27;t terribly common.  Most would be running zOS (<a href="https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Z&#x2F;OS" rel="nofollow">https:&#x2F;&#x2F;en.wikipedia.org&#x2F;wiki&#x2F;Z&#x2F;OS</a>) or TPF. Their VM hypervisor is also commonly used.