MPE/iX, Multiprogramming Executive with Integrated POSIX, is the latest
in a series of forward-compatible operating systems for the HP 3000
line of computers.
In HP documentation and in talking with HP 3000 users, you will
encounter references to MPE XL, the direct predecessor of MPE/iX.
MPE/iX is a superset of MPE XL. All programs written for MPE XL
will run without change under MPE/iX. You can continue to use MPE XL
system documentation, although it may not refer to features added to
the operating system to support POSIX (for example, hierarchical
directories).
Finally, you may encounter references to MPE V, which is the operating
system for HP 3000s, not based on PA-RISC architecture. MPE V
software can be run on the PA-RISC (Series 900) HP 3000s in what
is known as compatibility mode.
