NoSQL Options Compared, March 19, 2013 A Developer's Look at the Primary NoSQL Options
License Type: Apache for Community Edition, proprietary for high-end features.
Operating System: Linux, Mac OS X, UNIX, Windows
Implementation Language: C, C++, Erlang
Initial Release: 2011
Originally designed by the Memcache team, Couchbase was intended to be a fast key-value store/cache aimed primarily at Web apps. It later added the ability to persist data and handle complex queries. Data is stored in JSON documents.
The implementation relies on nodes that are all architecturally the same: They all contain a data manager, data, and a cluster manager component. A cluster manager supervises the configuration of all servers in a cluster, including replication and reballancing.
Like MongoDB and some other products in this list, Couchbase has a free community edition, but more advanced features require a commercial license from the sponsoring company.