Developer ports Mac OS 7.5.5 to the Apple Watch

Using the  Mini vMac emulator, developer Nick Lee was able to run Mac OS 7.5.5 on his Apple Watch with watchOS 2.  First spotted by MacRumors, an accompanying video showcases the surprisingly snappy performance of the legacy desktop OS on the watch wearable.  

System 7 debuted in 1991, with version 7.5.5 arriving in 1996. The operating system was originally designed for Quadra and PowerBook hardware, but was transitioned to the Intel-based PowerPC during its development.