My college roommate was the maintainer of Hercules, the z&#x2F;OS emulator.<p>See: <a href="http:&#x2F;&#x2F;www.hercules-390.eu&#x2F;hercfaq.html" rel="nofollow">http:&#x2F;&#x2F;www.hercules-390.eu&#x2F;hercfaq.html</a><p>2.01 Can it run z&#x2F;OS, z&#x2F;VM, z&#x2F;VSE?<p>Yes. Hercules is a software implementation of z&#x2F;Architecture, and so it is capable of running z&#x2F;OS, z&#x2F;VM, and z&#x2F;VSE. Hercules also implements ESA&#x2F;390 (including SIE) and so it can run OS&#x2F;390, VM&#x2F;ESA, and VSE&#x2F;ESA, as well as older versions of these operating systems such as MVS&#x2F;ESA, MVS&#x2F;XA, MVS&#x2F;SP, MVS&#x2F;SE, VM&#x2F;SP, VSE&#x2F;SP, and DOS&#x2F;VSE.<p>But (and this is a big but), these operating systems are all IBM Licensed Program Products, whose conditions of use generally restrict their usage to specific IBM machine serial numbers. So you cannot just copy these systems from work and run them on your PC, as this would almost certainly be a violation of your company&#x27;s licensing agreement with IBM.