Actegories

If you saw TFA and thought "hmmm yes, I know some of those words", then I can recommend the author's own lecture series on YouTube [0]. It's an intro to and overview of category theory aimed at programmers, with the requisite context and motivation for why anyone should care. It's long but worth the time investment IMHO.

0: http://www.youtube.com/playlist?list=PLbgaMIhjbmEnaH_LTkxLI7...

this has a real "a monad is a monoid in the category of endofunctors" energy to it

I'd like to understand how and why this stuff is useful for programmers.

Uh thanks but I'm gonna stick with Scattergories for now.