Automatic Link Checker  

Features: Administration area to add, delete, modify pages to monitor - You can give the address of your web site to which links should point - Cron file to send you daily report on which Link Partners are still linking back to you through crontab - Configure parameters of the script through password protected admin panel.

Hosting Requirements: PHP, Crontab
Database: MySQL
Price: $10

   Linked popularity check  

Linked popularity check is a PHP script that checks the search engines to see how many links a site has. Linked popularity check can check both Yahoo! and Google.

Hosting Requirements: PHP 4.0.4+
Price: Free

   Dead Link Script  

This script will check the availability of all the image url's in your database. If it finds that one of the images isn't available it will "suspend" the user's account and send an email notifying the user that their account has been suspended.

Hosting Requirements: Unix, Windows NT
Price: $5

   iDevRecipLinkCheck  

This program is designed for website owners who have reciprocal links that need checked often. It's perfect for "directory" or "listing" style sites that require link reciprocation. It's easy to catch cheaters who are not displaying your link. Works with an existing database of URLs or you can check one site at a time. Supports both automatic (from a database) and manual (one time) checking features.

Hosting Requirements: Linux; Apache; PHP 4;
Database: MySQL
Price: $39.95

   LinkPop Analyzer  

This script automatically queries MSN, Hotbot, AOL, Altavista, AllTheWeb and reports on link popularity.

Price: $25

   LinkBack Checker Lite  

This script can be extremely customizable, most users can even use this script to learn the process of checking links, and are able to write their own code. This script works good for when you have a link system requiring users to link back to you. This script makes sure that they do have a link on their site to you. All you need to do is enter the link you are looking for in the preferences section of the file, then point your browser and go.

Price: $10

   Little Cat Z  

Little Cat Z is conceptually very simple. It downloads the Category page and parses it for links. Each link is then filtered to dispose of search engine requests, a manual connection is established to the server and the page is requested. If the server is unreachable, the link is printed in red followed by the status code and error message. If the server is reachable, the page is requested and the status code is printed. In the case of a 3xx or 4xx error message lcz re-requests the page with an 'fopen' command. If the page is still unloadable, the link is printed in red followed by the status code. If the page loads properly, the link is printed in green with the status code and an (erroneous) message.

Hosting Requirements: Unix, Windows; PHP 4
Price: Free

   URL Checker  

PHP based Link Checker.

Price: Free

   LinkBack Checker Pro  

Professional Reciprocal Links Checker. This is a great script if you have several websites that you need to keep track of if they are linking back to you or not. This script stores a list of websites you want to check in a database. This allows for multiple simultaneous searches. Also provides the ability of multiple search links. Other features include quick search for on the fly manual search of a website. Also, this script has the capability of searching all of the links that are listed on your webpage. It can figure out what links are being shown on your site, and then it checks if those sites are also linking back to you. Powerful yet easy to use.

Price: $16

   Link popularity checker  

The link popularity checker enables you to enter a list of domain names that will check their link popularity in several major search engines including Google, HotBot / Inktomi, MSN, Overture and Yahoo. Link popularity is the amount of web pages in each search engine index that currently link to a specified domain name.

Hosting Requirements: Unix; PHP 4.1+; ionCube/Zend Optimizer
Price: $29.95