Really Simple Login (RSL) is a stateless, lightweight PHP authentication script with a small footprint to allow you to create secured pages and files on your web site.
RSL has only one purpose, and that’s to make sure the browser requesting your protected pages has permission to do so. If the request is authenticated, then the web page will be displayed, but if not the visitor will be asked to log in before they can view the contents.
RSL can be used with a MySQL database or a simplified PHP flat file to store your users in a CSV format instead if you’d like. The choice is yours.
RSL was designed to work on a LAMP stack (for the non-techies, that’s Linux, Apache, MySQL and PHP.) If your server is running Windows it may still work, but you’ll have to give it a try to find out.
RSL is free (as in beer), opensource and licensed under the GNU license v3, and was designed to be used as is, or it can serve as a simple starting point for you to extend the code to meet your unique needs.