   (when radian-customize-tweak-colors
     (set-face-background 'helm-buffer-saved-out nil)))
 
-;;;; Package: Company
-;; Shows autocompletion suggestions in a pop-up menu while typing. Includes
-;; interop with CIDER.
-;;;;
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;; Package: Projectile
+
+(when (member 'projectile radian-packages)
+
+  ;;; Enable Projectile everywhere.
+  (projectile-global-mode 1))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;; Package: Undo Tree
+
+(when (member 'undo-tree radian-packages)
+
+  ;;; Turn on Undo Tree everywhere.
+  (global-undo-tree-mode 1)
+
+  ;;; Override the default binding of M-/ to dabbrev-expand.
+  (global-set-key (kbd "M-/") 'undo-tree-redo)
+
+  ;;; Make undo history persistent between Emacs sessions.
+  (setq undo-tree-auto-save-history t)
+
+  ;;; Put all the undo information in a single directory.
+  (setq undo-tree-history-directory-alist '(("." . "~/.emacs-undos"))))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;; Package: ace-jump-mode
+
+(when (member 'ace-jump-mode radian-packages)
+
+  ;; Clojure mode already binds C-c SPC to clojure-align, so use C-c C-SPC
+  ;; instead.
+  (global-set-key (kbd "C-c C-SPC") 'ace-jump-mode))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;;; Package: Company (and company-statistics)
 
 (when (member 'company radian-packages)
 

  "Removes the provided package from radian-packages, if it is present."
  (setq radian-packages (delete package radian-packages)))

;;;; User-specific configuration (1 of 4).
(radian-load-user-config "init.before.local.el")

;;;; Appearance

;;; Disable the "For information about GNU Emacs..." message at startup,
;;; for *all* users.

(setq package-pinned-packages
      '((cider . "melpa-stable")))

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;; User-specific configuration (2 of 4)

(radian-load-user-config "init.pre.local.el")

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;; Install and activate packages

;;; Initialize the package management system, before we start trying
;;; to add packages.
(package-initialize)

;;; Install required packages, if necessary.
(unless (cl-every 'package-installed-p radian-packages)
