Top "Monoids" questions

A monoid is a set that is closed under an associative binary operation and has an identity element I ∈ Such that for all a ∈ S, Ia = aI = a. Note that unlike a group, its elements need not have inverses.

A monad is just a monoid in the category of endofunctors, what's the problem?

Who first said the following? A monad is just a monoid in the category of endofunctors, what's the problem? And …

haskell monads category-theory monoids
monoid vs monad in Scala

I have recently tried to find a good source on the difference between monads and monoids. Could someone provide a …

scala functional-programming monads monoids