Simple/Light-weight User management in PHP Web App

Simple/Light-weight User management in PHP Web App

I am using JQuery-mobile and buit a web app. I am looking for integrating some out of the box "user management" module instead of handcoding.

Features that I expect are as follows:

1. Have a CAPTCHA enabled + e-mail activated registration process with a defined set of fields.

2. Have a way to subscribe/unsubscribe (or completely delete) account features.

3. Let FaceBook/Gmail/OpenID be alternative login channels.

4. Anything that is relevant to the general lifecycle of user management.

Technology stack: JQuery-mobile + PHP + MySQL. So, ideally a PHP based implementation will do.

Please let me know if anyone around here has direct experience with anything available out there (commercial or opensource that allows customization).