EllisLab/CodeIgniter — pull request #2573 by mattpotts (2013-07-31 21:33:56+00:00)
Title: allow route overriding of root URI

To cover the case where you want `example.com/` to use a non-default controller. For example:

$route[''] = 'blog/tagged/php';

If you want `example.com/` to be a page of blog posts tagged as php