One of the fastest embeddable key-value ACID database without WAL. libmdbx surpasses the legendary LMDB in terms of reliability, features and performance.
Bring RocksDB to PostgreSQL as an extension. It is the first foreign data wrapper (FDW) that introduces LSM-tree into PostgreSQL. The underneath storage engine can be RocksDB. The FDW also serves for VidarDB engine, a versatile storage engine for various workloads. See the link for more info about VidarDB engine.
BBoxDB is a scalable, highly available, and distributed data store for multi-dimensional big data. The software supports operations like multi-dimensional range queries and spatial joins. In addition, data streams are supported.
Kunlun-storage is the storage component for Kunlun distributed DBMS. It's developed based on percona-mysql-8.0.x and contains exclusive features used by Kunlun distributed DBMS, performance enhancements and XA transaction crash safety enhancements without which MySQL would not be able to execute XA transactions reliably.