Update README.md

README.md

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 [![Code Climate](https://codeclimate.com/github/NodeBB/NodeBB/badges/gpa.svg)](https://codeclimate.com/github/NodeBB/NodeBB)
 [![Documentation Status](https://readthedocs.org/projects/nodebb/badge/?version=latest)](https://readthedocs.org/projects/nodebb/?badge=latest)
 
-**NodeBB Forum Software** is powered by Node.js and built on a Redis database. It utilizes web sockets for instant interactions and real-time notifications. NodeBB is compatible down to IE8 and has many modern features out of the box such as social network integration and streaming discussions.
+**NodeBB Forum Software** is powered by Node.js and built on either a Redis or MongoDB database. It utilizes web sockets for instant interactions and real-time notifications. NodeBB is compatible down to IE8 and has many modern features out of the box such as social network integration and streaming discussions.
+
+Additional functionality is enabled through the use of third-party plugins.
 
 * [Get NodeBB](http://www.nodebb.org/ "NodeBB")
 * [Demo & Meta Discussion](http://community.nodebb.org)