Mongo DB Data Provider
MongoDB DataProvider is a DataProvider for Sitecore that allows you to run a Sitecore database on MongoDB (?http://www.mongodb.org/) instead of SQL Server or Oracle. MongoDB is a NoSQL database that offers document-oriented storage. This is a good fit with CMS data.
WARNING: Please note that this module is highly experimental and has not been used in production environments. Use it at your own risk.
Check http://hermanussen.eu/sitecore/wordpress/2012/05/making-sitecore-faster-with-mongodb/ for more information.