Building frontend + backend : best practices ?

[eluser]Isuka[/eluser]
I'm going to try the way you guys doing. Clearly having models and libraries shared between frontend and backend is really advantageous.

What was great with my method I could quickly and easily make the backend app private with an .htaccess and .htpasswd in the admin folder (for small site it was sufficient for my clients). I'm curious how you make that with the admin in the controllers directory. With a complete authentification module ?