IBM System z servers are supported by a multitude of operating systems, such as z/OS, z/VSE, z/TPF, Linux on System z and the z/VM hypervisor.

IBM Systems are supported by a multitude of operating systems, such as z/OS, z/VSE, z/TPF, Linux on System z and the z/VM hypervisor.

The only real high end operating system runs on the IBM mainframe system now named IBM system Z. The actual system software is called Z/OS. It is used in banks and large corporations and has been around in various incarnations since the 1960's. The IBM system Z also runs Linux.

Also high end are:

The IBM power platform runs the IBM I system (a descendant of the IBM system/38 and AS/400), a corporate branch workhorse. It also run IBM AIX (a version of original unix) as well as Linux.

The HP OpenVMS system, known for its security features, stability and long uptime runs on the Intel Itanium platform which also runs a HP-UX (a version of unix) and Linux.

os for IBM

Bradford Hinson has written:

'z/VM and Linux on IBM System z' -- subject(s): Client/server computing, Operating systems (Computers), Virtual computer systems