Raven DB!

MongoDB (from "humongous") is a scalable, high-performance, open source NoSQL database. The database is document-oriented so it manages collections of JSON-like documents. Many applications can thus model data in a more natural way, as data can be nested in complex hierarchies and still be query-able and indexable.

Apache CouchDB is a distributed, fault-tolerant and schema-free document-oriented database accessible via a RESTful HTTP / JSON API. It includes incremental map / reduce mechanics for queries and keeps data safe with an append-only datastore.

RethinkDB pushes JSON to your apps in realtime.

Apache Cassandra has become the leading NoSQL platform driving many of today's modern business applications by offering continuous availability, high scalability and performance, strong security, and operational simplicity while lowering overall cost of ownership.

Couchbase is the NoSQL database market share leader, with production deployments at AOL, Deutsche Post, NTT Docomo, Salesforce.com, Turner Broadcasting Systems, Zynga and hundreds of other organizations worldwide. Couchbase products enable a more flexible, scalable, high-performance, and cost-effective approach to data management than relational database solutions and are particularly well suited for web applications deployed on virtualized or cloud infrastructures, and mobile applications requiring real-time data synchronization between devices and the cloud. Couchbase is a privately held company funded by Accel Partners, Ignition Partners, Mayfield Fund and North Bridge Venture Partners. www.couchbase.com »

Cockroach is a distributed key/value datastore which supports ACID transactional semantics and versioned values as first-class features. The primary design goal is global consistency and survivability, hence the name. Cockroach aims to tolerate disk, machine, rack, and even datacenter failures with minimal latency disruption and no manual intervention. Cockroach nodes are symmetric; a design goal is one binary with minimal configuration and no required auxiliary services.

HBase is an open source, non-relational, distributed database modeled after Google's BigTable and is written in Java. It is developed as part of Apache Software Foundation's Apache Hadoop project and runs on top of HDFS (Hadoop Distributed Filesystem), providing BigTable-like capabilities for Hadoop. That is, it provides a fault-tolerant way of storing large quantities of sparse data.

The Document-Graph database, SQL and Native Queries, asynchronous commands, intents, and much more.

NosDB is a 100% native .NET Open Source NoSQL Database. It is extremely fast and linearly scalable. Accelerate your development with a flexible JSON schema.

Azure DocumentDB is a NoSQL document database service designed from the ground up to natively support JSON and JavaScript directly inside the database engine. It’s the right solution for web and mobile applications when predictable throughput, low latency, and flexible query are key. Microsoft consumer applications like OneNote already use DocumentDB in production to support millions of users.

Titan is a scalable graph database optimized for storing and querying graphs containing hundreds of billions of vertices and edges distributed across a multi-machine cluster. Titan is a transactional database that can support thousands of concurrent users executing complex graph traversals in real time.

TayzGrid is an elastic in-memory data grid with a self-healing peer to peer dynamic data grid clustering architecture. TayzGrid is extremely fast and linearly scalable data grid and provides intelligent replication for data reliability without compromising on scalability. Add servers to the in-memory data grid cluster and grow transaction and storage capacity linearly.

FleetDB offers a flexible and expressive data model designed for the needs of modern application developers; a combination of schema-free records, declarative queries, automatically maintained indexes, and an optimizing query planner make it easy to manipulate and retrieve data. By keeping all data in RAM as persistent data structures, FleetDB is able to offer multi-record transactions, excellent concurrency semantics, and high performance. Writing to an append-only log provides durability in the form of a single file that can be transfered and analyzed using standard Unix tools. FleetDB is accessible via a simple JSON-based protocol that is implemented by clients in several programming languages. »

Persevere is designed to create applications with user interface implemented primarily on the client side and Persevere playing the role as an HTTP-based RESTful data provider.

VoltDB is a blazingly fast NewSQL database system. It is specifically designed to run on modern scale-out architectures - fast, inexpensive servers connected via high-speed data networks.