Devise - Flexible authentication solution for Rails with Warden

Devise is a flexible authentication solution for Rails based on Warden. It supports Database Authentication, Sends emails with confirmation instructions and verifies whether an account is already confirmed during sign in, Reset password and sends reset instructions, tracks sign in count, timestamps and IP address, Locks an account after a specified number of failed sign-in attempts and lot more.

It is composed of 10 modules: Database Authenticatable: hashes and stores a password in the database to validate the authenticity of a user while signing in. The authentication can be done both through POST requests or HTTP Basic Authentication.

Omniauthable: adds OmniAuth (https://github.com/omniauth/omniauth) support.

Confirmable: sends emails with confirmation instructions and verifies whether an account is already confirmed during sign in.

Recoverable: resets the user password and sends reset instructions.

Registerable: handles signing up users through a registration process, also allowing them to edit and destroy their account.

Rememberable: manages generating and clearing a token for remembering the user from a saved cookie.

Trackable: tracks sign in count, timestamps and IP address.

Timeoutable: expires sessions that have not been active in a specified period of time.

Validatable: provides validations of email and password. It's optional and can be customized, so you're able to define your own validations.

Lockable: locks an account after a specified number of failed sign-in attempts. Can unlock via email or after a specified time period.