EJDB is an embedded JSON database engine. It aims to be a fast MongoDB-like NoSQL library that can be embedded into C/C++/Nodejs/Python3/Lua applications. It features collection-level write locking, collection level transactions, string token matching queries, and a Node.js binding.
UnQLite is a in-process software library which implements a self-contained, serverless, zero-configuration, transactional NoSQL database engine.It is a document store database similar to MongoDB, Redis, CouchDB, etc. as well a standard key/value store similar to BerkeleyDB, LevelDB, etc. It reads and writes directly to ordinary disk files. A complete database with multiple collections is contained in a single disk file. The database file format is cross-platform, and you can freely copy a database between 32-bit and 64-bit systems or between big-endian and little-endian architectures.