OS/2
IBM i
IBM OS/6
Z/OS
FlexOS
Workplace OS
OS/360 and successors
Hierarchical File System (IBM MVS)
4690 Operating System
IBM System/360 Model 50
IBM System/370
IBM AIX
High Performance File System
ZFS (z/OS file system)
Houston Automatic Spooling Priority
Windows-1252
Control Language
CP/M-86
GEOS (16-bit operating system)
Virtual DOS machine
Gecko (software)