OPENSTEP for Windows NT
This screenshot is confusing.
At first glance, it looks as expected. Interface Builder running on Windows NT 3.51.
Bottom right is Visual C++? Perhaps its used in place of Project Builder?
It would be some interesting history to learn about.
I found the screenshot on google images for the search term "OPENSTEP for Windows NT"
Comments
http://mirror.macintosharchive.org/ca.cdn.preterhuman.net/mac/OpenStep-NeXTStep/OpenStep Enterprise Edition/
It could be required, or just happens to be running.
I didn't mention it, but the link from macintosharchive.org is working. I tested it in Windows NT 4 (virtualbox) and its working with the "Windows 95 look and feel" unlike the screenshot with that old NT 3.51 / win 3.1 look:
The name of the product isn't actually called Openstep for Windows NT. Its called OPENSTEP Enterprise https://en.wikipedia.org/wiki/OpenStep#OPENSTEP_Enterprise
This is not available on winworldpc.com. I didn't open a request to offer because original media is required.
Also, the filenames on https://winworldpc.com/product/nextstep/4x are named incorrect and should be renamed to OPENSTEP for Mach https://en.wikipedia.org/wiki/OpenStep#OPENSTEP_for_Mach
Seems it works in both NT 3.51 and NT4. Here's NT 3.51.