HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Scrapy - Scrapy | A Fast and Powerful Scraping and Web Crawling Framework
WebCopy - Cyotek WebCopy is a free tool for copying full or partial websites locally onto your harddisk for offline viewing.
Apache Nutch - Apache Nutch is a highly extensible and scalable open source web crawler software project.
SiteSucker - SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet.
Heritrix - Heritrix is the Internet Archive's open-source, extensible, web-scale, archival-quality web...