The IO monad for Scala
cats transformer type classes.
Principled, fast, typeclass derivation.
Tiny independent libraries with a single purpose, often a single class
Purely functional testing in Scala
Seamless interop layer between cats and scalaz
A BSON libary for scala using typeclasses
Date and time types and instances
Simple, fast, debuggable generic derivation for typeclasses
Scalaz typeclasses <~> Playframework2 typeclasses