HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Visualping - Visualping is the easiest to use website checker, webpage change monitoring, website change detector and website change alert software of the web. Read more about Visualping.
ScrapBook - ScrapBook is a Firefox extension, which helps you to save Web pages and manage the collection.
Distill Web Monitor - Distill is a web monitoring tool. It can monitor RSS feeds, a webpage or a part of webpage. Alerts in the form of pop-up, audio or emails can be received.
Archivarix - Online website copier and Internet Archive downloader. Download all files from a website include scripts and images. Free CMS included! Clean and workable code of rebuilt sites, external links removing, Wordpress adaptation.
Wachete - Track web page changes and get notified. Free Sign-up. Have all data in one place