MongoDB

MongoDB (from "humongous") is an open source, scalable, high-performance, schema-free, document-oriented database written in the C++ programming language.

Overview
MongoDB is designed for problems without heavy transactional requirements that aren't easily solved by traditional RDBMSs, including problems which require the database to span many servers.

Like other document-oriented database systems such as CouchDB, MongoDB is not a relational database management system. The database manages collections of JSON-like documents which are stored in a binary format referred to as BSON.

MongoDB on Dreamhost
Dreamhost does not allow installation of MongoDB on its shared server.

You must purchase a Dreamhost Virtual Private Server (VPS), where there is an option to install MongoDB automatically. Modules for allowing access to MongoDB from Perl, Ruby, Python, and PHP are also automatically installed by Dreamhost VPS.

To enable MongoDB on Dreamhost VPS:
 * Go to "Configure Server" under VPS
 * Switch MongoDB option from inactive to active
 * Click Save, and MongoDB is installed on your Dreamhost VPS!!!

Articles

 * Eric Lai. (2009, July 1). No to SQL? Anti-database movement gains steam
 * June 2009 San Francisco NOSQL Meetup Page
 * Designing for the Cloud at MIT Technology Review
 * EuroPython Conference Presentation
 * Non-relational data persistence in Java using MongoDB - Software Engineer at MongoDB
 * Interview with Mike Dirolf on The Changelog about MongoDB background and design decisions