In the old Engines plugin (used before the built-in engines arrived in rails 2.3), controller and helper classes were mixed together. That is, if an engine had a FooController, and your application also had a FooController, you could use the actions in both controllers. In the built-in Engines ...

Seamless UJS for Rails using NinjaScript. Get RESTFul delete links that work without JavaScript and AJAXy behavior that degrades gracefully right out of your scaffold!

Machine learning library in Ruby

A Ruby mailing list library designed to be integrated into other applications.

A simple Presenter for use with arbitrary templating languages

Makes it easy to use money with mongoid

MongoHydrator takes a document, represented as a Ruby Hash, and efficiently updates it so that embedded references to MongoDB documents are replaced with their corresponding subdocuments.

mongoid plugins

Library for translating Mongoid documents, based on Globalize3 principles

A tiny mongoid extension to provide the `touch` method known from ActiveRecord to Mongoid::Document.

Mongomatic is a modular Ruby object mapper for Mongo

Autodiscovers feeds from urls

Use the ms-dropdown (select dropdown with icons) in your Rails project :)

This gem will install as a daemon and can be used to connect to a graphite and a carbon backend. It will not only post the data for the metrics but also create graphs into graphite, by means of a translation from munin-node.

must_be provides runtime assertions which can easily be disabled in production environments. Likewise, the notifier can be customized to raise errors, log failure, enter the debugger, or anything else.

DB constraints in migrations similiar to ActiveRecord validations. Core classes

Postgresql constraints in migrations similiar to ActiveRecord validations

Naive Bayes classifier

This gem simulates named-parameters in Ruby. It's a complement to the common Ruby idiom of using Hash args to emulate the use of named parameters.

Natural provides a framework for answering 'naturally' worded questions like 'how many books did I buy last month' or 'list my Facebook friends'.