collection2csv is a lightweight engine on top of rails which lets you download active record collection to CSV with minimal syntax and provides support across associations. The initial version of the gem supported only single class collection.Later support was added to include associations. This gem was designed with the thought that it should allow developers to use it with just a single line of code after its integration. At present this gem has activerecord as its dependency. Future plans exists to provide support for mongoid and to extract its dependency from rails so that it can be used as a pure ruby library.