Adds zipcode validation methods to ActiveModel considering different country zipcode formats.

Simple model and validation mixins for RubyMotion

Robust options validation for methods.

A gem/plugin for Rails 3+ that enables client-side validation using ActiveModel + HTML5

Library for performing validations on DM models and pure Ruby object

Validations mixin for Ruby objects and support for Lotus

Rails plugin that maps model validations to class names on form elements to integrate with Validatious.

Phone number parsing, validation and formatting

Regressor generates regression specs based on ActiveRecord models. Currently relations, validations, attributes, and database indexes are supported.

A Ruby wrapper for the World Wide Web Consortium’s online validation services.

Adds reflective access to validations

ActiveRecord Tableless Models provides a simple mixin for creating models that are not bound to the database. This approach is useful for taking advantage of the features of ActiveRecord such as validation, relationships, etc.

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.

Includes a couple of core functions such as callbacks, timestamping, typecasting and lots of generic validation routines.

Client Side Validations for Rails 2.x and 3.x

Machinery is a systems management toolkit for Linux. It supports configuration discovery, system validation, and service migration. It's based on the idea of a universal system description.

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

cucumber-api allows API JSON response validation and verification in BDD style.

Minimalist validation matcher

Add a validation filter to your controller.