MDN was on Django 1.2 for a while, albeit with monkeypatched password hashing (since Django at the time was still defaulting to SHA1, I believe). With the switch to Persona, it no longer matters -- for a new account -- what hasher is used, since Persona doesn't involve storing a password.
[1] https://docs.djangoproject.com/en/1.5/topics/auth/passwords/...
[2] https://docs.djangoproject.com/en/dev/releases/1.4/