hydra_attribute is an implementation of EAV pattern for ActiveRecord models.

Rails I18n library for ActiveRecord model/data translation using PostgreSQL's JSONB datatype. Translations are stored directly in the model table rather than shadow tables.

Organizes ActiveRecord models into a tree/hierarchy using a materialized path implementation based around PostgreSQL's ltree datatype. ltree's operators ensure that queries are fast and easily understood.

A user-centric flagging extension for Rails 3 applications.

Ruby gem that automatically adds a lock timeout to all Active Record migrations

never let an unscoped Model.all accidentally leak data to an unintended audience.

Loader to solve N+1 issue for good.

Extend Ruby on Rails ActiveRecord with Neo4j nodes. Keep RDBMS and utilize the power of Neo4j queries. Originally by @elado.

Store nested hashes and other types in ActiveRecord hstores

Write-through and Read-through Cacheing for ActiveRecord

Disables observers during testing, allowing you to write model tests that are completely decoupled from the observer.

Off The Rails ActiveRecord: Use ActiveRecord with Grape, Sinatra, Rack, or anything else! Formerly known as 'grape-activerecord'.

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.

pg-eyeballs is a ruby gem that gives you detailed information about how the SQL queries created by the active record code you write are executed by the database. It gives you an easy, ruby friendly way to see the output of the Postgres EXPLAIN command and integrates with the popular query analysis tool gocmdpev

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

Declaratively filter data via URL params, in any Rack app.