HailDB was a fork of MySQL's InnoDB storage engine to provide it as a shared library with NoSQL API. It was part of the failed Drizzle project.
The last release of HailDB was in 2011. The project was then closed in 2015.
Embedded
B+Tree
Key/Value
http://www.haildb.com/
https://launchpad.net/haildb
http://www.haildb.com/documentation/
Stewart Smith
AU
2010
2015
Open Source
MySQL