Wikipedia
FoundationDB was a multi-model NoSQL database with a shared nothing architecture. The product was designed around a "core" database, with additional features supplied in "layers." The core database exposes an ordered key-value store with transactions. The transactions are able to read or write multiple keys stored on any machine in the cluster while fully supporting ACID properties. Transactions are used to implement a variety of data models via layers.
The FoundationDB Alpha program began in January 2012 and concluded on March 4, 2013 with their public Beta release. Their 1.0 version was released for general availability on August 20, 2013. The latest stable version, 3.0.2, was released on December 10, 2014.
On March 25, 2015 it was reported that Apple has acquired the company. A notice on the FoundationDB web site indicated that the company has "evolved" its mission and would no longer offer downloads of the software.