MongoDB vs CouchDB
A brief comparison
Both fully open source?
Which is more modern?
MongoDB has been started from 2007, first public release 2009. CouchDB graduated from Apache_Incubator in 2008. They are basically the same age.
Which has better documentation?
Both have good documentation, enough to get started quickly. MongoDB seems to have more details on their documentation.
Which has a stronger support of Rest?
CouchDB, one of main goals of CouchDB’s goal is to build a database for Rest
Who have had already compared the MongoDB and CouchDB?
Which is faster?
This article tested around 250 MB size file. It is found MongoDB is faster than CouchDB. There is also another benchmark data test. It also found MogoDB is faster than CouchDB for the heavy load of query condition. This is another article impressed by the efficiency of MongoDB.
Which is easier to work with?
CouchDB requires mapreduce style query. MongoDB relies on the traditional SQL style query. MongoDB also supports PHP integration more easily. If you are using PHP, then this is a nice plus.
On the MongoDB official site, there is a fair comparison of the durability. CouchDB is with crash-only design. Database can terminate at any time, MongoDB takes a different approach. Reparidatabase() operation has to be run once there is an unexpected termination.