Use rx for regex construction for great justice.

starter-kit-defuns.el

@@ -80,7 +80,8 @@
 
 (defun pretty-lambdas ()
   (font-lock-add-keywords
-   nil `(("(?\\(lambda\\>\\)"
+   nil `(((rx (opt "(")
+              (group "lambda" word-end))
           (0 (progn (compose-region (match-beginning 1) (match-end 1)
                                     ,(make-char 'greek-iso8859-7 107))
                     nil))))))

starter-kit-eshell.el

@@ -4,7 +4,12 @@
 
 (setq eshell-cmpl-cycle-completions nil
       eshell-save-history-on-exit t
-      eshell-cmpl-dir-ignore "\\`\\(\\.\\.?\\|CVS\\|\\.svn\\|\\.git\\)/\\'")
+      eshell-cmpl-dir-ignore (rx bos (or (and "." (opt "."))
+                                         "CVS"
+                                         ".svn"
+                                         ".git")
+                                 "/"
+                                 eos))
 
 (eval-after-load 'esh-opt
   '(progn
@@ -18,9 +23,9 @@
      (add-to-list 'eshell-visual-commands "ssh")
      (add-to-list 'eshell-visual-commands "tail")
      (add-to-list 'eshell-command-completions-alist
-                  '("gunzip" "gz\\'"))
+                  `("gunzip" ,(rx "gz" eos)))
      (add-to-list 'eshell-command-completions-alist
-                  '("tar" "\\(\\.tar|\\.tgz\\|\\.tar\\.gz\\)\\'"))
+                  `("tar" ,(rx (group (or ".tar" ".tgz" ".tar.gz" eos)))))
      (add-to-list 'eshell-output-filter-functions 'eshell-handle-ansi-color)))
 
 (provide 'starter-kit-eshell)

starter-kit-lisp.el

@@ -17,10 +17,10 @@
                   (delete-file (concat buffer-file-name "c"))))))
 
 (font-lock-add-keywords 'emacs-lisp-mode
-			'(("(\\|)" . 'paren-face)))
+			`((,(rx (or "(" ")"))  paren-face)))
 
 (font-lock-add-keywords 'scheme-mode
-			'(("(\\|)" . 'paren-face)))
+			`((,(rx (or "(" ")"))  paren-face)))
 
 (define-key lisp-mode-shared-map (kbd "C-c l") "lambda")