Like RocksDB from which this appears to be forked, the primary usage is as a storage engine for other applications/databases. Compared to rocksdb, it seems like ToplingDB has added more facilities to better support distributed use-cases.

Some databases that utilize RocksDB for their storage engine: https://kvrocks.apache.org/ - Redis/ValKey compatible distributed database with disk persistence via RockDB. https://github.com/pingcap/tidb - MySQL compatible distributed database. Mentioned elsewhere in this thread. https://github.com/tikv/tikv - Distributed, transactional, key value store. Originally by the same company as TiDB.

In theory you could use it as an in-process KV store similar to how SQLite provides an in process sql database, but the api is far from ergonomic for that use case.