Mini Windows 3.11 could be run on 2.88MB Floppy Disk! Of course, your computer must installed a 2.88MB Format Floppy Disk Drive first. It also supports RAM Disk for operation. I think it may deisgned for industry use on that time. Just for some machines that require a Windows 3.x based software as controller.
More detail about it
Sorry, no official web site could be found. No major commuitee is still mataining this thing. Several forums or blogs described this stuff in detail. They also shares useful experience on that kind of Windows. Try to find it out by any famous search engine.
If you want to enjoy anything surrounding Windows 3.x world, I suggest you stick on FreeDOS, MSDOS7.1(Not released by Microsoft actually), …, and setup a full version of Windows 3.x operating system.