z/OS is the latest in a long history of names for the high-end IBM mainframe operating system that began as OS/360 in the mid-1960s on the System/360. The most recent previous names were OS/390 and MVS.
This category is for websites that involve or cover the IBM mainframe computer operating systems: z/OS, OS/390, all versions of MVS and even OS/360 and its immediate successors. And its components, including Unix System Services (USS).
Technically, ISPF is IBM's Interactive System Productivity Facility, included with z/OS. It runs on TSO and provides a menu-driven interactive way to do common programming-related tasks, most notably: full screen editor, batch job submission, copy and dataset creation, compile and link-edit programs.
As well as information on ISPF itself, ISPF-related software products/companies should go here.