• Easy to set up: configure and upload the files and you're ready to run
• User-friendly interface
• Search, edit, and delete members easily
• Easily protect many different directories all through the same interface
• New members can be set to pending, awaiting admin approval
• "Cash-in" code feature allows you to send a one-time use code to a buyer which they can cash in for a membership. This is great for selling wholesale memberships as well as giving you an easy way to distribute memberships when you accept many different types of payments.
• Mass email all members, or just certain protected areas or expired members
• Customizable mass emails
• Backup the mysql database to a text file
• One step "reminder" feature quickly lets you send an email to a member to remind them of their login info as well as other promotions
• An advanced server log analyzer that gives you a server log summary as well as monitors the log for distributed passwords or hack attempts. Integrates directly with the membership manager to delete/inactivate bad accounts.
• Accounts can be deactivated and reactivated with the click of a button
• Includes a page where members can change their email address or have their login info emailed to them
• Integrates with all payment systems. In the worst-case scenario you can just accept any type of payment, even mail in checks, and send out "cash-in" codes for memberships.
• Header and footers customize the look of member's info pages

What is .htaccess?

Rather than go into major detail here, I'll just refer you to a great tutorial on htaccess and how it works:

http://www.freewebmasterhelp.com/tutorials/htaccess/