The monadics vocabulary is an alternative implementation of Haskell-styled Functors, Applicatives, and Monads to that found in the old monads vocabulary. This vocabulary implements Monad instances for:

Maybe

Either

sequence

Functors represent data structures which can be lazily mapped over:
Functors

The notion of "mapping" is equivalent to raising a unary function to a more abstract sturcture. Applicatives extend this notion to functions with any number of inputs:
Applicative Functors

Monads are the class of data structures for which there exists a notion of sequential ("And then...") operation:
Monads

Monadic Implementation Quirks