Last night saw the 3rd Oxford Raspberry Jam meetup, and I was able to demonstrate my Pi running Windows 95.
This was at the same time a joke and a serious demonstration of the Pi's capability. My apologies to the mods if this is not entirely on-topic for this particular forum, I ran Windows 95 in a Bochs virtual x86 machine over Debian rather than as a Pi operating system in its own right.
It was just about usable, despite no effort having gone in to tuning the Bochs setup. I can think of no practical application for Windows 95 on a Pi, but it is not impossible that perhaps someone might have to run a piece of legacy DOS software somewhere and might find Bochs a useful means to do it.
Anyway, a few tech details. Bochs is in the Debian repository, so a simple apt-get installed it. I installed Windows 95 from the CD that came with a laptop in the '90s to a 100Mb Bochs hard disk image on my desktop PC and transferred it to the Pi on a USB disk. The Pi has no CD-ROM drive and I didn't fancy trying to extract the ISO file to do the task. I used the X-windows Bochs display library, so the Debian desktop was always present in the background of the Windows 95 session. A much faster result could probably have been achieved had I compiled the SVGAlib package and run it without X, but this was more a demonstration for the laughs than practicality. As I said, "You've seen an open OS on your Pi, now here's a wide-open one!".
I make and sell radio kits for the Raspberry Pi and more.