I've really enjoyed "Functional JavaScript - Introducing Functional Programming with Underscore.js". I almost didn't get it because the use of underscore was a

I've really enjoyed "Functional JavaScript - Introducing Functional Programming with Underscore.js". I almost didn't get it because the use of underscore was a bit of a concern (the library is great but I felt I wanted to learn FP with "pure" JS). It was a fairly big step up from the intro to JS I read before (Eloquent JS) but it's a fantastic book. Jam packed with good stuff. I think the writing is a bit dense at times but the content is gold.