Great for storing user preferences

APN on Rails is a Ruby on Rails gem that allows you to easily add Apple Push Notification (iPhone) support to your Rails application. This version includes an association between an assumed User model and APN::Device

sqlite3 driver for RDBI

find_by_param is a nice and easy way to handle permalinks and dealing with searching for to_param values

A friendship library with a certain follower/following system utilizing the power of both Redis and SQL. Using SQL for the users and Redis for the followers and the followings. Redis uses sets of usernames for both your followers and followings. And can be used to retrieve more information about your e.g. followers from SQL with those unique usernames.

A Redis-backed voting extension for Rails applications.

Syncs your AR models with Braintree (Payment Gateway) and offers a lightweight reoccurring billing script

Enables the creation of scenarios that involve creating a rails project, starting and stoppping of servers, generating projects, editing files, issuing http requests, running of commands, etc. Output is captured as a single HTML file that can be viewed locally or uploaded. Additionally, there is support for verification, in the form of defining assertions based on selections (typically CSS) against the generated HTML.

This gem auto-generates ExtJS compatible model specifications from your ORM (eg: ActiveRecord, DataMapper, MongoMapper)

SexItUp allows for the easy drop-in of public domain images for site mockups and user avatars.

Use SimpleAdmin to build out filtering, searchable, editable interfaces for your models

Social Stream is a Ruby on Rails engine providing your application with social networking features and activity streams. This gem allow you to add events as a new social stream activity, with a calendar-supported management

Debug SQL statements in ActiveRecord by displaying warnings on bad queries.

Harker means Rails deployments via RubyGems--because a package manager is a terrible thing to waste.

Typed serialize makes sure your serialized attribute is always the specified type.

Abacus is an xdxf parser and semantic toolset for Ruby.

Dynamic attr_accessible for Active Record, inspired by Ryan Bates Railscasts episode 237

Utilizing ActiveRecord migrations to enable data migrations independently from schema migrations.

A way to get cottage cheese out off activerecord

ActiveRecord model inheritance support by module.