Authentication
User login and authentication with Joomla database
VTEM Login
The VTEM Login Module is pretty much a copy of the default Joomla Mod_login Module. It's very easy to use, and there're very few parameters to set.
Ninja Join Now
The Ninja Join Now module allows you create a professional Web 2.0 application style front page for your site, increasing the professional look of your site and the trust it generates for customers. Which means increased signups. Position up to 6 ima ...
SP Popup Login 
SP Popup Login is a simple log in/out module with a simple modal url. Users just click the link and a popup window opens for user to log in. If there is present a log in menu item, then the popup uses it. It is multi-language and not any configuration ...
Simple Registration
This component allows user to register by inserting only an e-mail address: it will be used both as "Full name" and "Username"; password will be created randomly and sent to the user. To use this component, just create a menu item which links to Simple R ...
login as any user
This plugin handles Joomla's default user authentication, but also allows an admin to login in as any user with just the admin password.
SJ Login, Register and Contact
SJ Login, Register and Contact – a new Joomla extension is finally launched today! This product will provide you a real way of making your visitors feel extremely comfortable with the process of login, contact and register on your website. Most of webs ...
PraiseRegister 
Joomla! Registration in a Module! PraiseRegister is a simple yet powerful module that allows you to place a registration form on any page, in any module position on your site.