Link Checker (CMD)  

Checks all the links on a website from a given URL for dead links and other fatal error codes. Keeps track of the total number of links on your website and identifies both living and dead links. Saves the last scan to text file for later viewing.

Price: Free

   LinksChecker  

This script checks all external and internal links on page and gives out their quantity and their status.

Price: Free

   Linking Reporter  

The Linking Reporter tool is a small utility script that allows you to query the search engines to see how websites link to your website. This query can be based upon a search term. Not only does this allow you to see how many other Websites link to your Website but also how well your competitors rate and who your competitors are in any chosen field or search terms.

Hosting Requirements: Unix/Linux
Database: MySQL
Price: $25

   Link Restrictor  

Link Restrictor makes the impossible possible by giving you the power to check up on your link partners with the click of a button. Never before has it been easier to make certain those who display your banner ads or hyperlinks are actually holding up their end of the bargain.

Hosting Requirements: Unix/Linux, Windows

   Echelon Link Checker  

With this simple script you simply edit a few variables at the top of the script, set a url to the page you want, and it will go to that page, get all the links, and check each link to see if its "dead" or not.

Price: Free

   AFFA  

An AFFA link page can spice up your web site. It enables your visitors to add links of interest for other users to find. The AFFA script is virtually maintenance free, and has been designed to be abuse and spam proof.

Hosting Requirements: Unix, Windows
Price: Free

   Link Popularity  

Find out how many sites are linking to yours according to six search engines. This includes Altavista, Hotbot, Lycos and more.

Price: Free

   Reciprocal Link Checker  

RLC is a useful tool that performs reciprocal links checking automatically. Simply tell it which are the remote web pages you wish to monitor and the URL of your links. It will then crawl the remote web pages and feedback to you the latest status (found, link not found or page not found/network error).

Price: $49.95

   404 Manager  

404 Manager is a script that allows a webmaster to easily and quickly view which requests on your account are returning 404 errors, and which pages are linking to those files that are not found. 404 Manager also keeps real time stats on how many times a URL was returned as a 404, and which urls referred that 404 request. Stats are kept overall, current month, current day, and amount since last checked.

Price: Free

   XLinks  

Link validator for XHTML web pages. Based on XML parsing methods, this script allows a high degree of control on a page-by-page and link-by-link basis. Able to crawl entire sites.

Price: Free