Do you have that Windows 3.1 version that came with the Compaq that had the DE that was like a paper folder instead of an empty desktop, and that you could put the icons in the different tabs of the paper folder?
I don't think I've heard of an alternate shell/launcher like that before. Do you remember what it was called?
Your comment reminds me of HP's obscure EFI OS called QuickLook. I would guess there are a lot of obscure OSs out there.