An awesome nested set implementation for Active Record

Write-through and Read-through Cacheing for ActiveRecord

Create and modify your notifications through a simple API.

Integrates with your authentication solution to craft a personalized user notification platform.

A ruby library for working with the Open Archive Initiative Protocol for Metadata Harvesting (OAI-PMH)

use pagy for cursor-based pagination with rails

Extends Paperclip with Dropbox storage.

If you like the straight forward and effective nature of Strong Parameters and suspect that CanCan might be overkill for your project then you'll love Petergate's easy to use and read action and content based authorizations.

Amazon Redshift _makeshift_ adapter for ActiveRecord 4.

Adds missing native PostgreSQL data types to ActiveRecord and convenient querying extensions for ActiveRecord and Arel

Easily write arbitrary filters

A lightweight cron scheduler for the Que async job worker

Adds the ability to pull random records from ActiveRecord

A modern fast tagging framework for Rails 3.1+

Better support for legacy database schemas for ActiveRecord, such as columns named class, or any other name that conflicts with an instance method of ActiveRecord.

SchemaValidations extends ActiveRecord to automatically create validations by inspecting the database schema. This makes your models more DRY as you no longer need to duplicate NOT NULL, unique, numeric and varchar constraints on the model level.

A smart sms verification tool

State machine that allows dynamic transitions for business workflows

Sharding

Introspects your database string field maximum lengths and automatically defines length validations.