load

(defun my-load-all-in-directory (dir)
  "`load' all elisp libraries in directory DIR which are not already loaded."
  (interactive "D")
  (let ((libraries-loaded (mapcar #'file-name-sans-extension
                                  (delq nil (mapcar #'car load-history)))))
    (dolist (file (directory-files dir t ".+\\.elc?$"))
      (let ((library (file-name-sans-extension file)))
        (unless (member library libraries-loaded)
          (load library nil t)
          (push library libraries-loaded))))))