Model.validates { presence_of :name }

Manage your Amazon Kindle highlights: Sync and cache to an ActiveRecord database and output in various formats

Better Stack Rails integration

ManageIQ Appliance Console

MerbAdmin is a Merb plugin that provides an easy-to-use interface for managing your data

Microscope adds useful scopes targeting ActiveRecord boolean and datetime attributes.

Low-tech search for ActiveRecord with MySQL or PostgreSQL

Ruby wrapper for Amazon CloudSearch (aws-sdk), with ActiveRecord, Mongoid support for easy integration with your Rails application

Writer methods parameters normalization

Octoball provides Octopus-like database sharding helper methods for ActiveRecord 6.1 or later, using Rails' native horizontal sharding handling. This provides migration path to Rails 6.1+ for applications using Octopus gem with older Rails.

once-ler supercharges your let's and before's with the performance of before(:all)

Migrations

OvirtMetrics is an ActiveRecord-based gem for reading the oVirt History database.

locale-specific attachments with paperclip and globalize

Allow Paperclip attachments to be stored on FTP servers

A Solar Hijri (Jalali) date library for Ruby, whitch provides much of Ruby's built-in date class

Pecorino allows you to define throttles and rate meters for your metered resources, all through your standard DB

Auto-order table columns for optimize disk space usage

ActiveRecord extension for querying hstore and jsonb.

ActiveRecord extensions for PostgreSQL. Provides useful tools for schema, foreign_key, index, function, trigger, comment and extension manipulations in migrations.