https://forum.winworldpc.com/discussion/11422/openstep-for-w...
It even survived Apple's purchase of NeXT, where the OpenStep API was renamed Yellow Box. There was a port of Yellow Box to Windows:
https://www.betaarchive.com/forum/viewtopic.php?t=29049
In both OpenStep Enterprise and Yellow Box for Windows, while the UI elements still have some NeXT-isms, it's not terribly out of place, either.
However, this got scrapped sometime when Apple abandoned Rhapsody (which had PowerPC and x86 versions) in favor of Mac OS X (which was originally only available for PowerPC until the Intel switch in 2006, though Apple maintained an x86 version internally during the PowerPC years). During the transition from Rhapsody to Mac OS X, Yellow Box was renamed Cocoa.