Nowadays in-browser Javascript is able to execute algorithms in under 1 second that would have taken tens of minutes or hours to compute in the late eighties. Back then, even a dumb spell-checker like that one implemented by Peter Norvig in Python, would have been problematic and was considered a major feat. If a software engineer from the eighties would travel forward in time, he'd be amazed that we are carrying super-computers in our pockets.