Codex has some info on it overall: Accessibility WordPress ATAG Evaluation More Solution For performance is it better to build custom functionality into the theme or a plugin in WordPress widgets - Dynamic Sidebars On Multiple Subpages in WordPress errors - All new plugins generating 311 chars of unexpected output? in WordPress Plugin that provides the [edit] shortcode? in WordPress Define menu_order on Creation of New Custom Post? in WordPress Reffered: https://wordpress.org/
