Likewise, some points in the talk brought to mind the OO SOLID principles. It's unfortunate that much of the discussion I saw on HN and twitter after this talk

Likewise, some points in the talk brought to mind the OO SOLID principles. It's unfortunate that much of the discussion I saw on HN and twitter after this talk was argument about the value and purpose of testing. More useful would be examining the point of the talk and considering any common ground between Rich's "Simplicity Toolkit" and where things stand now with languages that aren't Clojure. Take your language of choice. If you're not in a Lisp already, you can't do much about syntax vs. data, but what about the rest? Is it easy to work generically with data and values instead of making custom classes and mutable objects for every piece of data? Is it possible? Can we make it better? Are there persistent collections or managed refs available? Can we write them as libraries? Within the language's polymorphism construct, can we extend a type we don't control to our abstractions without creating adapters and more complexity around value and identity? What about transactions?