Where is skeletal animation?

Hello everyone, I am currently at day 70 of handmade hero, and yesterday I saw that even in the last episodes (day 250 or so) there is no trace of the skeletal animation system.
When has Casey planned to implement it?

I'm asking this because I would like to start programming small games from myself with the notions that I already have, but I really need a better understanding of animation... and I would like to start using skeletal animation instead of sprite sheets.

Can you point me towards some good books/tutorial on the subject?
(I ve already heard of "the illusion of life: disney animation", and I think I will buy it)

Thank you in advance, and sorry for my awful english.

Leonardo
It's a 2D game so there should not be a need for skeletal animations. Maybe he'll start it when he makes the hero's "walk" cycle which IIRC is still non-existent.

As for animation books I've heard that The Animator's Survival Kit by Richard Williams is the reference guide to look at. It's for 2D but a lot of the principles will be valid for 3D.
Handmade hero already has a very limited skeletal animation system -- the Hero is built from a body, cape and head that are separate bitmaps drawn together with their own offsets. You could try, say, animating the head offset to make it bob up and down as the hero walks around. I suspect that since the hero has no arms or legs, Casey is probably going to try to keep the animation system pretty simple.

If you want to learn about this, I'd suggest trying a tool such as "Spriter" or "Spine" which support 2d skeletal animation rigs. Try to write something that can load and playback the example files from one of those, first using their sample importers, and then try writing it again from scratch.