tiedot is a document database engine that uses JSON as document
notation; it has a powerful query processor that supports advanced set
operations; it can be embedded into your program, or run a stand-alone
server using HTTP for an API.

tiedot has fault-tolerant data structures that put your data safety
first, while easily scales to 4+ CPU cores.

tiedot has very stable performance, even with millions of records! It
consistently achieves high throughput - swallow more than 120k records
or 80k complicated queries per second with confidence.