That depends on what the customer does, no? > However, z/OS also implements 64-bit Java, C, C++, and UNIX (Single UNIX Specification) APIs and applications thr

That depends on what the customer does, no? > However, z/OS also implements 64-bit Java, C, C++, and UNIX (Single UNIX Specification) APIs and applications through UNIX System Services – The Open Group certifies z/OS as a compliant UNIX operating system – with UNIX/Linux-style hierarchical HFS[NB 3][NB 4] and zFS file systems. These compatibilities make z/OS capable of running a range of commercial and open source software.[3] z/OS can communicate directly via TCP/IP, including IPv6,[4] and includes standard HTTP servers (one from Lotus, the other Apache-derived) along with other common services such as SSH, FTP, NFS, and CIFS/SMB. https://en.wikipedia.org/wiki/Z/OS https://en.wikipedia.org/wiki/Z/OS Although I like the argument that having an OS that does not require use of C is an interesting feature. Then it's really about the quality software platform, more than about the magic hardware.