RethinkDB - The open-source database for the realtime web
ObjectBox - ObjectBox empower edge computing with an edge device database and synchronization solution for Mobile & IoT. Store and sync data from edge to cloud.
MongoDB - MongoDB (from "humongous") is a scalable, high-performance NoSQL database.
CompactView - Viewer for Microsoft® SQL Server® CE database files (sdf)
CouchDB - HTTP + JSON document database with Map Reduce views and peer-based replication
HSQLDB - hsqldb: Full-featured 100% Java ORDBMS