Dynamic languages are easy to implement. Type systems that are rigorous enough to be useful but flexible enough to be expressive are much, much harder to design

Dynamic languages are easy to implement. Type systems that are rigorous enough to be useful but flexible enough to be expressive are much, much harder to design. I think we're still not quite there yet but we've made a lot of progress in the last decade. Even after ten years of Ruby experience I find myself writing code in Scala that has fewer bugs and is vastly easier to understand and maintain. Maybe my background in chemistry colors my view but I don't see 54 years as really such a long time for any intellectual discipline. We're still in the early days of software engineering, IMO.