Re: "the result of 40 years of technology"
Some operating systems of the 1960s were very sophisticated and ahead of their time. While the Burroughs B5500/5700/6500/6700 series machines did not have internet connectivity, the operating system (Master Control Program or MCP) did support many interactive terminals, multiprogramming, virtual memory and powerful programming languages.
https://play.google.com/store/books/details/Computer_System_Organization_The_B5700_B6700_Serie?id=CiijBQAAQBAJ&hl=en-US