gistfile1.txt

(require 'cl)
(require 'package)
(add-to-list 'package-archives
             '("marmalade" . "http://marmalade-repo.org/packages/") t)
(add-to-list 'package-archives
	      '("melpa" . "http://melpa.milkbox.net/packages/") t)
(package-initialize)

(unless (package-installed-p 'dash)
	(package-refresh-contents)
	(package-install 'dash))

(require 'dash)

(defun ensure-packages (package-list)
  (unless (-all? #'package-installed-p package-list)
    ;; check for new packages (package versions)
    (message "%s" "Installing more packages...")
    (package-refresh-contents)
    (message "%s" " done.")
    ;; install the missing packages
    (-each
     (-reject #'package-installed-p package-list)
     #'package-install)))



(ensure-packages '(project-explorer))
(require 'project-explorer)