Scalaz

http://timperrett.com/2014/07/20/scalaz-task-the-missing-documentation/

https://www.infoq.com/presentations/Scalaz-Functional-Programming-in-Scala

https://hseeberger.wordpress.com/2010/11/25/introduction-to-category-theory-in-scala/

https://hseeberger.wordpress.com/2011/01/31/applicatives-are-generalized-functors/

http://eed3si9n.com/learning-scalaz/

https://www.infoq.com/presentations/Scalaz-Functional-Programming-in-Scala