Monads in Joy, a concatenative language: https://web.archive.org/web/20100816085746/http://www.latrobe.edu.au/philosophy/phimvt/joy/j04alg.html
miniblog.
Related Posts
On building intuitions on monads and functors: https://www.jerf.org/iri/post/2958
(Also, TIL that the function type is a functor in Haskell!)
Very readable discussion of different ways of expressing applicative and monads in ocaml. Discusses the necessary operators and new syntactic sugar:
Free monad considered harmful https://markkarpov.com/post/free-monad-considered-harmful.html
Excellent, pragmatic blog post discussing usage of free monads, performance, and when you can simply use typeclasses.