About BLT
BLT (Better Link Tester) is a link checker.

- Easy to Use: Use BLT just as you would a web browser. Type in your address, or use a file browser, and sit back and watch. Quickly filter the results by status or by text. Results can be viewed either “flat” or as a “tree.”
- Document Based: Create BLT Documents that remember the settings and results from previous checks. Control the default document settings in the Preferences.
- Export: Create HTML, CSV/Text, or OmniGraffle files from the results. Exporting is done through loadable bundles, so you can write your own exporters to expand BLT.
- OS X Friendly: Uses the same URL caching mechanism as Safari, uses the Keychain for authenticated sites, results filtering by search field, etc.

Read more: http://www.apple.com/downloads/macosx/development_tools/blt.html