MySQL is the world's most popular open source database. With its proven performance, reliability and ease-of-use, MySQL has become the leading database choice for web-based applications, used by high profile web properties including Facebook, Twitter, YouTube, Yahoo! and many more.
Couchbase is the company behind the Couchbase open source project, a vibrant community of developers and users of Couchbase document-oriented database technology. Their flagship product, Couchbase Server, is a packaged version of Couchbase technology that’s available in Community and Enterprise Editions. They're known for their easy scalability, consistent high performance, 24x365 availability, and a flexible data model. Companies like AOL, Cisco, Concur, LinkedIn, Orbitz, Salesforce.com, Shuffle Master, Zynga and hundreds of others around the world use Couchbase Server for their interactive web and mobile applications.
MongoDB is the leading modern, general-purpose database platform, designed to unleash the power of software and data for developers and the applications they build. Headquartered in New York, MongoDB has more than 8,300 customers in over 100 countries. The MongoDB database platform has been downloaded over 45 million times and there have been more than one million MongoDB University registrations.