MongoDB is also a cross platform NoSQL DBMS, currently supporting Windows, Mac, Solaris, and various Linux distributions at the time of writing.

MongoDB is used by some of the largest companies in the world, including Facebook, Google, Nokia, MTV Networks, Cisco, Forbes, and many more.

Behind the scenes, MongoDB actually stores the JSON documents in a binary-encoded format called BSON. BSON extends JSON through supporting additional data types and to be efficient for encoding and decoding within different languages.

The Couchbase Data Platform includes Couchbase Server and Couchbase Mobile. Both of these are open-source, NoSQL, multi-model, document-oriented database management systems that store JSON documents.

Couchbase refers to its platform as the industry's first Engagement Database — a new class of database that can tap into dynamic data, at any scale and across any channel or device.

Couchbase (the company) began as NorthScale in 2009, and was subsequently renamed to Membase Incorporated in 2010. Couchbase, Inc. was then created through the merger of Membase and CouchOne in February 2011.

Couchbase customers include Amadeus, AT&T, BD (Becton, Dickinson and Company), Carrefour, Cisco, Comcast, Disney, DreamWorks Animation, eBay, Marriott, Neiman Marcus, Tesco, Tommy Hilfiger, United, Verizon, Wells Fargo, and more.

Apache CouchDB is a document oriented open source database management system that uses JSON natively.

CouchDB was first released in 2005 and later became an Apache Software Foundation project in 2008.

Couch is an acronym for cluster of unreliable commodity hardware.

CouchDB is reportedly used by companies such as Amadeus IT Group, Credit Suisse, npm, and the BBC.

Azure DocumentDB is Microsoft’s multi-tenant distributed database service for managing JSON documents at Internet scale. DocumentDB indexing enables automatic indexing of documents without requiring a schema or secondary indices. DocumentDB is designed to provide real-time consistent queries in the face of very high rates of document updates.

MarkLogic is considered a multi-model NoSQL database for its ability to store, manage, and search JSON and XML documents and semantic data (RDF triples).

MarkLogic was initially based on XML, but has since evolved to natively store JSON documents and RDF triples.

MarkLogic customers include Aetna, BBC, Boeing, Broadridge Financial Solutions, Dow Jones, McGraw Hill Financial, NBC, Wiley, U.S. Army, U.S. Navy.

OrientDB is an open source NoSQL database management system written in Java. It is a multi-model database, supporting graph, document, key/value, and object models, but the relationships are managed as in graph databases with direct connections between records.

OrientDB natively supports HTTP, RESTful protocol, and JSON additional libraries or components.

OrientDB clients include Comcast, Sky, Cisco, Verisign, Ericsson, United Nations, and Warner Music Group.

RethinkDB is the first open-source, scalable JSON database built from the ground up for the realtime web. RethinkDB is designed specifically to push data to applications in realtime.

Riak is a distributed NoSQL key-value data store that offers high availability, fault tolerance, operational simplicity, and scalability. In addition to the open-source version, it comes in a supported enterprise version and a cloud storage version.

Although Riak wasn’t explicitly created as a document store, it does have features that make it possible to store and query JSON objects or XML.

BaseX is a native and light-weight XML database management system and XQuery processor, developed as a community project on GitHub.

Although it's an XML database, its JSON module contains functions to parse and serialize JSON documents.

Elasticsearch is a search engine based on Lucene. It provides a distributed, multitenant-capable full-text search engine with an HTTP web interface and schema-free JSON documents. Elasticsearch is developed in Java and is released as open source under the terms of the Apache License. Elasticsearch is the most popular enterprise search engine followed by Apache Solr, also based on Lucene.

Elasticsearch users include Wikimedia, Adobe Systems, Facebook, Stack Exchange, Quora, Mozilla, Netflix, and more.

MySQL is the world’s most popular open source DBMS. MySQL is used by some of the largest organisations in the world, including Facebook, Google, Twitter, Adobe, Flickr, Alcatel Lucent, Zappos, YouTube, and many more. It is also used by many smaller scale projects such as personal websites or blogs.

MySQL 5.7.8 introduced a native JSON data type that enables efficient access to data in JSON. This includes optimized storage, and automatic validation of JSON documents stored in JSON columns. Invalid JSON documents will produce an error.

Oracle Database is an object-relational database management system produced and marketed by Oracle Corporation. Oracle Database is one of the world’s most popular RDBMSs.

Although Oracle Database is an object-relational database, it does support JSON (and XML). It supports JSON natively with relational database features, including transactions, indexing, declarative querying, and views.

PostgreSQL (often referred to as Postgres), is an object-relational database management system (ORDBMS) with an emphasis on extensibility and standards-compliance.

PostgreSQL also has a number of JSON functions and operators that can be used with its two JSON data types (JSON, and JSONB).

PostgreSQL users include Apple, Fujitsu, Cisco, University of Sydney, University of California, Skype, Telstra, U.S. State Department, and many more.