I'm experimenting with Uncle Dave's config which is using a minimum init.el
to launch config.org, which is full of elisp babel source blocks. Here's
his relevant launching code:

(when (file-readable-p "~/.emacs.d/config.org")
  (org-babel-load-file (expand-file-name "~/.emacs.d/config.org")))

However, I've seen this example:

(require 'org)
(require 'ob-tangle)
(org-babel-load-file (expand-file-name "~/.emacs.d/myemacs.org"))

which seems to want (require 'ob-tangle). The Uncle Dave setup is working
fine. I guess I don't know how it's tangling (which means running all the
code blocks in the org file, right?) without somehow being told to. But
then what is org-babel-tangle-file doing other than running all the code
blocks in a file? And then there's the :tangle yes parameter on an
individual code block. I'm missing something here. It seems
org-babel-load-file is creating a config.el from the config.org -- which is
a tangle behavior.

LB