You would need a cursory knowledge of ml to be able to understand it, but you can implement the examples in plenty of other languages. The principles taught are fairly universal. (At least for the first half, I haven't made it beyond that yet...)
Yeah, I had a hard time getting into that book the first time around due to a lack of ML knowledge. Once you have some ML or Haskell I'd say it's worth a read.
Let Over Lambda forgot by whom
https://www.youtube.com/watch?v=0nbkaYsR94c Not technically a book, but watch it anyway.