A schema parsing and validation library for Ruby

Helpful rspec matchers for testing validations and associations.

Extra validations for Scrivener.

A gem that verifies the integrity of a state history

Description of StrongestValidations.

Tripwire captures validation errors from your Ruby on Rails application to help you identify and fix user experience issues. The TripwireNotifier gem makes it easy to hook up your app to the Tripwire web service.

Flexible and modular validations for ActiveRecord models

Library to parse X12 messages and manipulate their loops, segments, fields, composites, and validation tables.

YAML files loader with validation

Simple validation library with virtus integration

Brazilian zipcode validations for ActiveRecord, integrated with correios-cep gem.

ActiveRecord model validation against stopforumspam.com (Rails 3)

IAP and IAB receipt validation module.

A rails plugin to set the digested value before validation and validate uniqueness.

W3C Validators is a Ruby wrapper for the World Wide Web Consortium's online validation services.

Defined hashlike objects, with validations. For simple schema definitions and checking they're followed

WIP!!! escher sign and validation for faraday http rest client

Framecurve parser, validation and interpolation

ActiveRecord: Simple filtering for html as validation.

Apply ActiveModel validations at a model instance level