[seanmcdirmid]

I agree with this; Clojure's design is incredibly pragmatic about state, including mutable state, like any good Lisp.

People just tend to misinterpret this, or they digest it as "immutability good for live programming" when that isn't true: immutability is great for programming with values, but please don't make an immutable world object and replace it when something changes! Unless you are using Javascript, I guess there is just no other way to deal with the DOM other than diffing.