[willholley]

Although it's been a quiet few years, the project is on the up again. 2014 was a big year for CouchDB - CouchDB 2.0 developer preview was released (more on this in a sec) [1], IBM acquired Cloudant (and has made it available as on-premise offering), Cloudant Query (MongoDB-style querying for CouchDB)[2] was contributed to CouchDB. PouchDB, Couchbase Mobile and Cloudant Sync (all replication-compatible with CouchDB) all saw major new releases and increased uptake. Much more detail on all of this is on the CouchDB blog [3].

CouchDB 2.0 adds dynamo-style clustering support (similar to Riak and Cassandra) in addition to the replication(sync) protocol used by the CouchDB ecosystem [4]. It also includes all the fixes / performance improvements based on Cloudant's operational experience over the last 5 years.

That said, document databases are certainly a niche. CouchDB is a good choice if you need strong durability (writes are always fsync'd - to multiple copies when clustering) and consistent performance as your database scales (querying options may seem restrictive but are designed to scale very well). As others have pointed out, the RESTful interface to CouchDB makes it a good fit for web and mobile applications which can query the database directly without an app tier. PouchDB [5] and various mobile datastores which implement the sync protocol [6][7] allow you to also take your database to a browser or mobile client and work with it when disconnected which is pretty compelling.

[1] https://speakerdeck.com/wohali/putting-the-c-back-in-couchdb... [2] https://cloudant.com/blog/introducing-cloudant-query [3] http://blog.couchdb.org/2014/12/19/couchdb-weekly-news-decem... [4] http://www.replication.io/ [5] http://pouchdb.com/ [6] https://cloudant.com/cloudant-sync-resources [7] http://www.couchbase.com/nosql-databases/couchbase-mobile