 Finally, NEST also defined an operating system interface known as "POSE" ("Portable Operating System Extension"), which was a thin translation module defining all of the calls NEST needed to support its own functionality, things like memory management and process creation (as POSIX 1003.1, 1003.4, and 1003.4A subsets), which the developer ported to the particular platform of interest.NEST was deliberately written to be able to run from ROM without secondary storage (i.e., it had no long-term state it needed to store).Whereas the Digital Research-inherited modular real-time multi-user multi-tasking operating system FlexOS was used by Novell as a primary test platform during development, NEST did not include an operating system of its own, and instead was intended to be used on existing platforms and OSs.