.. index:: single: Doctrine; Common extensions
Doctrine2 is very flexible, and the community has already created a series of useful Doctrine extensions to help you with common entity-related tasks.
One library in particular - the DoctrineExtensions library - provides integration functionality for Sluggable, Translatable, Timestampable, Loggable, Tree and Sortable behaviors.
The usage for each of these extensions is explained in that repository.
However, to install/activate each extension you must register and activate an :doc:`Event Listener</cookbook/doctrine/event_listeners_subscribers>`. To do this, you have two options:
- Use the StofDoctrineExtensionsBundle, which integrates the above library.
- Implement this services directly by following the documentation for integration with Symfony2: Install Gedmo Doctrine2 extensions in Symfony2