List 
Scalaz provides instances for Scala’s built-in List such as Monad and Equal.
Typical imports
import scalaz._
import Scalaz._
Use the type class instances
scala> val list1: List[Int] = List(1, 2, 3)
list1: List[Int] = List(1, 2, 3)
scala> val list2: List[Int] = List(1, 2, 3)
list2: List[Int] = List(1, 2, 3)
scala> list1 === list2
res0: Boolean = true
scala> list2.map(_ + 2)
res1: List[Int] = List(3, 4, 5)