A mobi site is supposed to be for mobile device use. But really it’s just a new choice for domain names in addition to .com and all the others. So it’s up to you on how you choose to the site to work, but it would be following convention to put a site designed for [...]

Big picture, Joomla and Drupal do the same thing. You can login to create and edit pages. They are both open source (free) and use the most common technologies (PHP and MySQL) available at hosting companies.
A close analogy might be automobiles, they both get you there but in different ways, styles, rides, etc. So which [...]