Since November 2010, I have been writing an Erlang driver for MongoDB. After many months of work, I would consider the driver production-ready, and wanted to take this opportunity to introduce the driver and highlight a few of the design decisions. For detailed documentation with code examples please see the links at the end of this article.
At the highest level, the driver is divided into two library applications, mongodb and bson. BSON is defined independently of MongoDB at bsonspec.org.