A third installment in a series highlighting lesser-known built-in Emacs features, covering 20 practical capabilities discovered over six years. Features include: dictionary-tooltip-mode for hover definitions, wildcard support in find-file and dired, ffap-menu for listing all URIs in a buffer, compare-windows for lightweight diffing, dired-compare-directories with custom predicates, highlight-changes-mode for tracking unsaved edits, augmented vc-diff commands that work with backup files, the full apropos command family, find-function-on-key for jumping to source, copy-from-above-command and duplicate-dwim for text duplication, kmacro-edit-lossage for turning keystroke history into macros, subword-mode and superword-mode for CamelCase/snake_case navigation, image display manipulation, visible-mode for revealing all hidden text, isearch-toggle-invisible, ruler-mode for setting margins interactively, refill-mode for true automatic text wrapping, scroll-all-mode for synced window scrolling, emacs-lock-mode to prevent accidental buffer kills, and undelete-frame-mode for restoring closed frames. Code snippets are provided for customizing several features.
