ForerunnerDB - ForerunnerDB is the only JavaScript database with a simple, rich JSON-based query language.
dBASE PLUS 10 - Object-Oriented Databases
Alasql - Alasql.js - is a lightweight client-side in-memory SQL database designed to work in browser and...
InterSystems Caché - Use InterSystems Caché advanced database for high-volume data. Learn more about how Caché analyzes unstructured data and handles transaction management.
PouchDB - Open-source JavaScript database inspired by Apache CouchDB that's designed to run well within the browser
VelocityDB - VelocityDB is an easy to use, extremely high performance, scalable, embeddable and distributable object database system with indexes for C# .NET applications with a small footprint (~ 600KB).