The PowerOpen Environment (POE), created in 1991 from the AIM alliance, is an open standard for running a Unix-based operating system on the PowerPC computer architecture.
The upcoming A/UX 4.0 (never actually released) would target the PowerOpen Environment ABI, merge features of IBM's AIX variant of Unix into A/UX, and use the OSF/1 kernel from the Open Software Foundation.
... Apple agreed to provide IBM with the technology needed to allow standard Macintosh applications—starting with the Finder—to run under the new AIX, much as they do under A/UX today.
Apple will apply the PowerOpen label to the new version of A/UX that results from the deal; IBM will do likewise with the new AIX.The need for the POE reduced due to the increasing availability of Unix-like operating systems on PowerPC, such as Linux distributions and AIX.
[4] The presence of the ABI specification in the POE distinguishes it from other open systems such as POSIX and XPG4, since it allows platform-independent binary compatibility, which is otherwise typically limited to particular hardware.