65: What are hilit19 and font-lock modes, what is the difference between them, and how do I customize them? Hilit19 and font-lock are two minor modes that syntactically highlight Emacs buffers using colors and fonts of your choosing. This is especially useful when editing code, since strings can be in one face, comments a second color, and function definitions a third. Both packages come with Emacs 19. Hilit19 is slower than font-lock mode, but is easier to customize and has regexps for more major modes. To invoke hilit19 automatically whenever you start Emacs, include the following Lisp forms (stolen from the documentation at the top of hilit19.el, which should be in your lisp directory) in your .emacs file: (cond (window-system (setq hilit-mode-enable-list '(not text-mode) hilit-background-mode 'light hilit-inhibit-hooks nil hilit-inhibit-rebinding nil) (require 'hilit19))) Note that hilit-background-mode should be set to 'dark (and not 'light) if your Emacs window has a dark background. Changing the default hilit19 face specifications requires the use of hilit-translate. See the comments at the top of hilit19.el for some examples of how to use hilit-translate, as well as for some basic instructions. Font-lock is faster than hilit19, but comes with fewer predefined regexps and supports fewer major modes. To enable font-lock for a particular mode, you will need to use the hook for that mode. For example, to turn on font-lock mode every time you load an Emacs Lisp file, add the following to your .emacs file: (add-hook 'emacs-lisp-mode-hook '(lambda () (font-lock-mode 1))) Customization of font-lock mode is done by setting the variables font-lock-comment-face, font-lock-string-face, font-lock-doc-string-face, and font-lock-function-name-face. You may define new reserved words by modifying the variable font-lock-keywords. If you want to use hilit19 for some modes and font-lock for others, you can use the variable hilit-mode-enable-list. See the documentation for that variable (using M-x describe-variable) for instructions on how to set it. You might also want to look at Simon Marshall's face-lock package, which handles fontification and provides an easier interface to font-lock. You can get face-lock from the Emacs Lisp Archive; see question 87.