Flexible authentication solution for Rails with Warden

A generalized Rack framework for multiple-provider authentication.

An unobtrusive ruby authentication library based on ActiveRecord.

Doorkeeper is an OAuth 2 provider for Rails and Grape.

Clearance is built to support authentication and authorization via an email/password sign-in mechanism in applications. It provides some core classes commonly used for these features, along with some opinionated defaults - but is intended to be easy to override.

Generates common user authentication code for Rails/Merb, with a full test/unit and rspec suite and optional Acts as State Machine support built-in.

Easily switch current user to speed up development

Provides common authentication needs such as signing in/out, activating by email and resetting password.

A gem providing Rails with authentication, Facebook Connect, MadMimi, and DelayedJob support

Simple CAS authentication for Rails, Sinatra or any Rack-based site

A full featured library for working with Microsofts Active Directory in Ruby.

Rails3 engine that adds OAuth2 Provider support to any application built with Devise authentication

Helper to simplify RPX Now user login/creation

WebAuthn ruby server library ― Make your application a W3C Web Authentication conformant Relying Party and allow your users to authenticate with U2F and FIDO2 authenticators.

Secure your application with multi-factor authentication, user activity monitoring, and real-time threat protection.

Rodauth is an authentication and account management framework for rack applications. It's built using Roda and Sequel, but it can be used as middleware in front of web applications that use other web frameworks and database libraries. Rodauth aims to provide strong security for password storage...

An authentication gem for the pre-production (mainly) phase of the application lifecycle. Provide a simple sign in page with a list of all users in the application. Click on any user logins you to the application under the user.

minimalistic authentication

Authorization that includes basic authorization and 3 social authorization with Latvia social network draugiem.lv, facebook.com and twitter.com.

simple rails authentication

A Simple has_secure_password implementation