Often abbreviated as ZOS, z/OS is IBM's
mainframe operating system. It is a
64-bitoperating
system that supports Java,
UNIX, API's, and
TCP/IP to name a few features. z/OS.e is a
specially priced, slimmed-down offering of z/OS. It provides select functions
but uses the same code base as z/OS and invokes an operating environment
that is comparable to z/OS in service, management, reporting, and reliability.
The first name for IBM's mainframe operating system was MVS
(Multiple Virtual Storage), which was succeeded first by OS/390 and then z/OS.