The QNX Demo Disk: a full xNix OS, with GUI and browser, on just 1 1.4MB floppy

Article note: The QNX demo floppy and BeOS PE installer were the high water marks for OS demos. It's such a shame the licensing situation around QNX has always been a little too distressing for it to really get traction, a little POSIX-like with first class RT that runs on commodity hardware is "right" for a ton of tasks.