Akamai-AuthToken is Akamai Authorization Token for Ruby 2.0+

A flexible authentication and authorization framework for Rack applications.

Users, Authorization and Authentication for Isomorfeus.

Another authorization gem

Contextual authorization for your Rails (3+) application

A command line OAuth authorization tool.

A description of a really simple authorization plugin for Rails.

Authorizr: A simple controller-centric authorization framework.

A simple and elegant solution to authorization suitable for most small and medium-sized projects.

Lightweight and framework-agnostic ruby authorization system.

Group access authorization control, based on controllers actions access permissions using ActionSentinel.

Sequel mixin for SimpleOAuth2 authorization

Lockdown is an authorization system for RubyOnRails (ver >= 2.1).

Controller level authorization

DSL-based permission rules for easy authorization logic in Rails

No magic authorization for Rails

Cannie is a gem for authorization/permissions checking on per-controller/per-action basis.

A Twitter API gem with OAuth 2.0 authorization (not ready for production)

A ready-to-go application with authentication, authorization, logging... with bootstrap flavor

Checkin is an authorization gem for Ruby on Rails