The Couchbase family will now include:

• Elastic Couchbase [Membase Server]: Membase Server, to be renamed Elastic Couchbase in a forthcoming release, will feature high-performance caching, elastic clustering and document database features. It can effortlessly scale from a single server to a hundred-node cluster supporting an application with millions of concurrent users.
• Couchbase: A lightweight, non-clustered Couchbase edition appropriate for developers and smaller Couchbase production deployments.
• Mobile Couchbase: Initially focused on the iOS platform, Mobile Couchbase is a database embeddable into native iOS applications. Mobile Couchbase provides data management services to applications whether off- or online, and can be configured to automatically synchronize with other Couchbase instances when network connectivity is established.
• Hosted Couchbase: Hosted Couchbase is a quick and easy way to get started with Couchbase, and provides a ready-made cloud sync point for applications built using Mobile Couchbase.

Both Membase and CouchDB have some high profile usages. Membase Server is used by Zynga, and CouchDB is used at CERN by scientists working on the Large Hadron Collider.

Both companies have been in identity crisis lately. Membase changed its name from Northscale in October, and CouchOne changed its name from Couchio to CouchOne in September.

"I'm a huge CouchDB fan - the geospatial indexing has enabled groundbreaking work in the world of open government apps. CouchOne joined with Membase will reshape how we view and use big data to make software more useful," says Code for America Fellow Max Ogden. Ogden created Couchappspora a CouchDB-based version of Diaspora (our resident hacker Tyler Gillies is also a contributor to Couchappora).