rainbow-delimiters.el:

RainbowDelimiters is a “rainbow parentheses”-like mode which highlights parentheses, brackets, and braces according to their depth. Each successive level is highlighted in a different color. This makes it easy to spot matching delimiters, orient yourself in the code, and tell which statements are at a given depth.

Great care has been taken to make this mode FAST. You shouldn’t see any change in scrolling or editing speed when it’s on even when working in delimiter-rich languages like Clojure, Lisp and Scheme.

You can customize the colors RainbowDelimiters uses. The default colors are intentionally subtle; they are unobtrusive enough to make the mode worth looking at even if you usually don’t like rainbow parentheses modes.

This is the official github repository for rainbow-delimiters. It is made available so people can easily contribute to the mode.

The latest release of rainbow-delimiters.el is always found at the following location on EmacsWiki:

• rainbow-delimiters.el

Further information is available on the EmacsWiki page:

• http://www.emacswiki.org/emacs/RainbowDelimiters

Installation instructions:

1. Place rainbow-delimiters.el on your emacs load-path.

2. Compile the file (necessary for speed):
   M-x byte-compile-file

3. Add the following to your dot-emacs/init file:
   (require 'rainbow-delimiters)

4. Activate the mode in your init file.
   You can choose to enable it only in certain modes, or Emacs-wide:

• To enable it only in specific modes, add lines like the following:
  (add-hook 'clojure-mode-hook 'rainbow-delimiters-mode)

• To enable it for all programming modes, add the following line (emacs 24 or higher):
  (add-hook 'prog-mode-hook 'rainbow-delimiters-mode)

• To activate the mode globally, add to your init file:
  (global-rainbow-delimiters-mode)

• To temporarily activate rainbow-delimiters mode in an open buffer:
  M-x rainbow-delimiters-mode

Additional discussion is at the top of the file and on the EmacsWiki page linked to above.