Joomla is fantastic because you could add or modify view or calculate intervening into particular events. It only needs to add or modify correct files. If you would like:

  1. modify template
    • creating your template in /templates/your-template-name and
    • overwriting css or html about modules or components
  2. modify modules
    • overwriting html from templates/your-template-name/html
    • from administration, copying module and add it with different parameters
    • copying module and install it as new module
    • changing module by your plugin
  3. add new plugins
  4. add new components

Zoo is a big component. It is so important that it has also more ways to add or modify view or calculate.
If you would like:

  1. modify template
    • from zoo administration interface
    • adding modules into zoo templates (full, related, item, teaser, ..)
  2. modify zoo component
    • from /media/zoo/applications with applications.php files
    • and all final files about full, related, item, teaser, .., templates