Phoundation  

Phoundation is an Object Oriented PHP framework for building secure web applications and generating personalized content. It can be used out of the box to create intranets, extranets and various other applications where content needs to be protected and seperated based on user, group and/or role permissions. Phoundation is also a self-hosting application, meaning that the access control and user management system is built upon itself.

Hosting Requirements: Unix, Windows
Database: MySQL
Price: Free to $7

   UMA  

UMA is a powerful tool for speeding the development of web sites and online applications written in PHP. In addition to providing a powerful user management and authentication system, UMA also provides a great database independent API. Features: Active development; Supports the latest version of PHP; Supports the MySQL database server (other databases will be implemented as needed); Easy to integrate into your existing codebase; Support as many web sites, applications or users as you need with one database and one UMA installation; Online administration tool for managing users and UMA services; Object-oriented design; Powerful database abstraction layer.

Hosting Requirements: Linux; Apache 1.3.xx; PHP 4.2.x
Database: MySQL 3.23.xx
Price: Free

   PassMasterFlex  

A simple single-user login that utilizes cookies for authentication. PassMasterFlex was written to provide an alternative to the Apache login, since the only successful way to "log out" with Apache is to close the browser window.

Price: Free

   Password Manager  

Generates .htpassword files online or offline.

Price: Free

   cleverSecure  

Use this security module and set special patterns for IP's that are authorised or denied to view your pages. cleverSource features: Unlimited IP patterns accepted - Customisable security error message - Doesnt depend on platform or browsers.

Price: Free

   Cookie Password Protection  

This script will help you password protect PHP pages. All you have to do is add one line of PHP code at the top of the pages you would like to protect. In version 2.5 you can have multiple user groups, and you can give access to your pages to one or more user groups. Your users can also change their passwords and email address.

Price: Free

   php login script  

This simple php login script features functions to add hashed and encrypted passwords and usernames to a mysql table, and then a function to validate users based on these PHP login credentials.

Price: Free (GPL)

   membersArea  

A set of files written in php, html, javascript and css that allow a user with php-hosting to add a secure area to their site. These files do not require a database as all data is recorded into a seperate flat-file.

Price: Free

   phpAutoMembersArea  

Automatically create your own members area, NO programming experience required. Included is a separate join page for your new members and separate members-area that only your members can access following a successful login. When a new member joins you can set the system to auto activation of new members or manual activation

Hosting Requirements: Unix/Linux
Price: Free

   page protect  

This guide will step you through a simple protection script that you can use on your site. This assumes that you do not have the ability to use .htaccess which would be the preferred option. This is not a 100% secure solution and as such, you should not rely on any scripts like these to protect sensitive data such as credit card details. Basically all you are doing is protecting your pages from general viewing by allowing only people with permission to access those pages.

Hosting Requirements: Linux, Windows
Price: Free