paredit-mode

;; Webpage: http://emacswiki.org/emacs/ParEdit
(require 'paredit)
(add-hook 'emacs-lisp-mode-hook		(lambda () (paredit-mode 1)))
(add-hook 'lisp-mode-hook		(lambda () (paredit-mode 1)))
(add-hook 'lisp-interaction-mode-hook	(lambda () (paredit-mode 1)))
(add-hook 'python-mode-hook		(lambda () (paredit-mode 1)))
(add-hook 'scheme-mode-hook		(lambda () (paredit-mode 1)))
(add-hook 'clojure-mode-hook		(lambda () (paredit-mode 1)))

;;https://github.com/grettke/parenface 
(require 'parenface)
(eval-after-load 'parenface
  (progn
    (set-face-foreground 'parenface-paren-face "SteelBlue4")
    (set-face-foreground 'parenface-bracket-face "SteelBlue4")
    (set-face-foreground 'parenface-curly-face "SteelBlue4")))
(setq show-paren-delay 0)

;; Webpage: http://www.emacswiki.org/emacs/HighlightParentheses
(require 'highlight-parentheses)
(define-globalized-minor-mode global-highlight-parentheses-mode
  highlight-parentheses-mode
  (lambda ()
    (highlight-parentheses-mode t)))
(global-highlight-parentheses-mode t)

;; swap () and [] keys
(define-key key-translation-map [?\(] [?\[]) 
(define-key key-translation-map [?\[] [?\(]) 
(define-key key-translation-map [?\)] [?\]]) 
(define-key key-translation-map [?\]] [?\)]) 

;; Stop SLIME's REPL from grabbing DEL,
;; which is annoying when backspacing over a '('
(defun override-slime-repl-bindings-with-paredit ()
(define-key slime-repl-mode-map
      (read-kbd-macro paredit-backward-delete-key) nil))
(add-hook 'slime-repl-mode-hook 'override-slime-repl-bindings-with-paredit)