Free and Open Source Document Database 2015
ArangoDB is a distributed free and open-source database with a flexible data model for documents, graphs, and key-values. Its query language AQL (ArangoDB Query Language) supports joins, graph queries, list iteration, results filtering, results projection, sorting, grouping, aggregate functions, unions and intersections. Transactions in ArangoDB are atomic, consistent, isolated, and durable (ACID).
BaseX is a light-weight, high-performance and scalable XML Database engine and XPath/XQuery 3.1 Processor, which includes full support for the W3C Update and Full Text extensions. An interactive and user-friendly GUI front-end gives good insight into XML documents. The product itself is completely Open Source (BSD-licensed) and platform independent. Client/Server architecture, supporting ACID safe transactions, user management, logging, and a wide range of interfaces: REST/RESTXQ, WebDAV, XQJ, XML:DB; clients in many different languages.
The Apache Cassandra database provides scalability, high availability and excellent performance. Linear scalability and proven fault-tolerance on commodity hardware or cloud infrastructure make a good platform for mission-critical data. Cassandra’s supports replication across multiple datacenters. Data is automatically replicated to multiple nodes for fault-tolerance. Replication across multiple data centers is supported. Failed nodes can be replaced with no downtime. Cassandra’s data model offers the convenience of column indexes with the performance of log-structured updates, strong support for denormalization and materialized views, and powerful built-in caching.
Couchbase Server is a high-performance NoSQL distributed database with a flexible data model. It scales on commodity hardware to support large data sets with a high number of concurrent reads and writes while maintaining low latency and strong consistency. Couchbase can be deployed as a document database, key/value store and distributed cache. It provides topology aware clients for Java, .NET, Node.js and more with a native JSON API and reactive extensions. The community edition is free, but for large scale applications the enterprise edition is recommended.
CryptonorDB, as the name suggests is security oriented (built-in encryption algorithms – AES and Camellia) and delivers high availability, fault tolerant database service accessible via a RESTful HTTP/JSON API. It enables enterprises to build always-on mobile / desktop / embedded applications that work regardless speed and reliability of the internet connection. CryptonorDB local mobile database may be synchronized with CryptonorDB cloud database with just one line of code. CryptonorStudio provides a user interface on Windows and Mac platforms. At the time of writing the platform is in beta, and a free subscription is available for modest requirements.
eXistdb is a NoSQL document database and application platform. It is a native XML database engine storing textual or binary data and documents without requiring a database schema. A Browser-based IDE allows managing and editing all artifacts belonging to an application, and it provides support for XML, JSON, HTML and Binary documents. All versions of eXistdb are Open Source and may be used in academic, non-commercial and commercial applications.
MongoDB is a popular document database that will support most types of data. It includes fully consistent indexes on any field, as well as geospatial, text search and TTL indexes. MongoDB’s query language provides varied field-level operators, data types and in-place updates. Drivers for just about any programming language make it intuitive to use.
OrientDB is a distributed graph database that supports ACID transactions, HTTP and JSON and replication. It also supports SQL with extensions to manipulate trees and graphs. The community edition is free.
Redis is an open source, BSD licensed, advanced key-value cache and store. It is often referred to as a data structure server since keys can contain strings, hashes, lists, sets, sorted sets, bitmaps and hyperloglogs.
RethinkDB is an open source database. It allows JSON documents to be queried with Python, Ruby, Node.js and many other languages. Joins are supported along with aggregation and map/reduce. It has a distributed architecture with sharding and replication.