LinkChecker - LinkChecker is a free, GPL licensed website validator.
Dr. Link Check - Broken link checker with malware and parked domain detection
Dead Link Checker - Check for broken links on any website
Beta Testers Hub - Early adopters network for your Startup
Scrutiny - Scrutiny for Mac helps you manage and improve any number of websites. Link check, search, full website spell check, XML sitemap generator, SEO audit
Passmarked - Simple, all-in-one test to check the quality of your website