I tested each link checker I found in VersionTracker and this one is the best. It not only checks for broken links, it also validates pages for HTML 4.01. Although it only does the Framework document type and I use Strict, it still helps find things that the W3C HTML validator misses. Other much more expensive apps are not as easy to use or as fast. I especially liked that the results can be saved in several formats and the report doesn't slow my whole system down just trying to bring up the HTML of the report in Firefox. The Firefox plug-in is nice but it only does one page at a time and doesn't let you save the results to work with later. WebLight does an entire site. You can save the results to recheck fixes, or clear the whole thing and recheck the site (I prefer that method because some fixes my affect many results). Support is also responsive and helpful.