[gren]

What I really like in this library is it provides an automatic case class <> json binding (so it's convenient) but without using any Reflection: It uses the Scala Macros and is type-safe. See also: http://mandubian.com/2012/11/11/JSON-inception/

[mandubian]

and naturally it provides real Json validation with error aggregation which is interesting in many cases (not only Web actually)