I recently made significant updates to my encyclopedia article on “Abilities” in the Stanford Encyclopedia of Philosophy. Changes include a more extensive review of modal theories of ability, discussion of important work on “two-way powers,” and a brief discussion of David Lewis’s theory of ability, initially outlined in 2000 year but published only recently.
The SEP is a dynamically updated resource so I would welcome any observations of typos, minor errors, etc. so that I can correct these. (More substantive criticisms are very much welcome too, though it may take me longer to address these).