Open Orchestra is an Open Source CMS built on the full stack framework. For database it uses a MongoDB, a NoSQL store rather than the more typical Relational Databases such as MySQL or PostgreSQL.
The project describes itself as a professional Symfony2/MongoDB CMS and it is licensed under the Apache license. While the project is not a household name in the squeeze of Symfony CMSes, the project still has significant effort behind it with over a hundred contributors in Github.
The system is very fully featured and has a lot of concepts that sound very familiar to Drupal developers, for example. Their terminology includes items such as nodes, content types, zones, blocks, themes and so on. Multisite installations are also there out of the box.
With being quite feature complete and focus on code quality through Continuous Integration, Open Orchestra is one of the options that is worth considering over the old players.