"Move from MongoDB to MySQL The current release depends on MongoDB. When we first created the application, we wanted to make sure we had a highly scalable application and database to meet our anticipated performance needs under high loads. We have been running MongoDB in production for over a year, but we have decided that the performance benefits it provides are outweighed by the complexity of trying to extend Drupal features backed by MongoDB. We are currently moving to a fully MySQL-backed application to increase the speed the development of new features and other aspects of maintaining the Drupal application. Our next release will be a dev branch that will be fully backed by MySQL, and once there is a tag for that branch, we will no longer maintain the MongoDB branch."