Compare Concrete5 vs. Joomla!
Concrete 5 is a long running content management system. It is known for it's user friendly interface and with it's recent iterations has moved to adopt Symfony components.
Joomla! is one of the big three PHP CMSes. Currently it uses only a single component from the Symfony project. Joomla remains a strong contender with a large number of users and extensions.
CMSes vailable for comparison: BackBee, Bolt CMS, Concrete5, Contenta, Contentful, Cosmic.js, Craft CMS, Drupal 8, eZ Platform, Fork CMS, GraphCMS, Grav, Jarves, Joomla!, Kunstmaan, October CMS, Open Orchestra, Pagekit, Pimcore, PyroCMS 3, Reservoir, Spress, Sulu CMS, Symfony CMF, Symphony CMS