Use Google Apps as an Authentication Provider

OmniAuth extension for vkontakte.ru authentication

Mozilla BrowserID/Persona authentication module that works with Rails 3.1+ and Devise 2.1+

An Active-Resource replacement that supports camel-cased APIs and HTTP caching, and avoids race conditions when changing authentication information on the fly.

Gem with common functionality for authentication using MojeID provider. Uses ruby-openid gem for this.

Merb plugin that provides authentication support

NoPassword is a Ruby on Rails gem that allows session authentication with a token or a magic link via an email sent to the user; there is no need for a password.

An extremely easy way to protect your site by requiring Google logins without having to set up a traditional authentication system

Firebase Authentication API wrapper for serverside. It support custom token auth. Of course it has id_token verify feature.

Ember-auth is an authentication framework for ember.js. It is expected to work out of the box with rails + devise.

The Google Sign-In API gives OAuth2 JSON Web Tokens (JWT) as response data upon user sign-in. A necessary step for a service provider to trust such a token is validatation. Accepting the token without validation would allow a malicious client to simply assert itself in your system. ...

A Sinatra Extension that simplifies using twitter for login and authentication.

Minimal CMS Rails Engine or more likelly a "static" pages manager. Pages can be created, deleted, edited and arranged into sections using a file tree like interface courtesy of jQuery tree (http://jstree.com). It attempts to be as minimal, flexible and unobtrusive as posible leaving a lot of fun...

Rack middleware for using the Authorization header with token authentication

Twitch authentication with OAuth 2. Result tokens can be used for API libraries, chat libraries or something else.

RackApiKey is a middleware that enables simple API key authentication

Enables verification of server-side authentication and user management for applications using Passage

dynamoid-devise is flexible authentication solution for Rails 4.1.x with Warden using dynamoid as ORM...

A reusable JWT authentication helper

TinderAuthFetcher enables you to retrieve a Facebook authentication token, which is necessary to use Tinder API