Software developer Nick Lee has hacked an iWatch running watchOS 2 to run a port of the nineteen-year-old Mac OS 7.5.5. MacRumors reported that he got the Mini vMac Macintosh emulator running on the iWatch and is running the 1996 era OS inside the emulator.
The following video doesn't show much but it does prove that the iWatch is powerful enough to simulate a two decade old OS:
When Mac OS 7.5 was released in September 1996 it required a chunky Power Macintosh 5500 with a high end PowerPC CPU. Now you can simulate the OS with a $400 smartwatch.
It's amazing how much progress we've seen n the past twenty years, isn't it?