I recently installed a new WordPress site as a replacement for an older site and I needed to redirect the old pages to the new site. I installed the WordPress redirection plugin in order to do this as it looked well supported and feature rich.
Joomla has literally thousands of extensions that add various bits of functionality to a Joomla based website. This article covers those Joomla extensions that I find particularly useful or well put together. You can find these and other extensions are the Joomla Extensions site.