Facebook, Google, LinkedIn and Twitter are teaming together on a new open source project called WebScale SQL. A branch of MySQL, the new project focuses on getting a traditional database to scale up and out to support the needs of the world's largest websites. WebScale SQl will "provide a common set of code changes that groups can use as a base to apply further changes that are relevant to their use case."
The group says that it chose to work with MySQL because it "has the production-ready features we need to operate at scale, and the features planned for MySQL 5.7 seem like a fitting path forward for us."
Code for the project can be found at Github.