Apache CouchDB, commonly referred to as CouchDB, is an open source document-oriented database

Document-oriented database

A document-oriented database is a computer program designed for storing, retrieving, and managing document-oriented, or semi structured data, information...

 written mostly in the Erlang programming language. It is part of the NoSQL group of data stores and is designed for local replication and to scale horizontally across a wide range of devices. CouchDB is supported by commercial enterprises Couchbase

Couchbase

Couchbase is a Silicon Valley-based enterprise software company which offers product "Couchbase ", plus sells support & training for these...

 and Cloudant

Cloudant

Cloudant is a Massachusetts-based enterprise software company which provides an open source non-relational, distributed database service of the same name that requires zero-configuration...

.
In April 2005, Damien Katz (former Lotus Notes

Lotus Notes

Lotus Notes is the client of a collaborative platform originally created by Lotus Development Corp. in 1989. In 1995 Lotus was acquired by IBM and became known as the Lotus Development division of IBM and is now part of the IBM Software Group...

 developer at IBM

IBM

International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...

; now founder, CTO of Couchbase) posted on his blog about a new database engine he was working on.