RocksDB is an embeddable persistent key-value store for fast storage. RocksDB can also be the foundation for a client-server database but our current focus is on embedded workloads. RocksDB builds on LevelDB to be scalable to run on servers with many CPU cores, to efficiently use fast storage, to support IO-bound, in-memory and write-once workloads, and to be flexible to allow for innovation.

ClustrixDB is a scale-out SQL database built from the ground up with a distributed shared nothing architecture, automatic data redistribution (so you never need to shard), with built in fault tolerance, all accessible by a simple SQL interface and support for business critical MySQL features – replication, triggers, stored routines, etc.

ToroDB is an open source, document-oriented, JSON database that runs on top of PostgreSQL, providing storage and I/O savings and ACID semantics. ToroDB is MongoDB-compatible, so you can use Mongo clients to connect to it.