HTTrack - HTTrack is a free (GPL, libre/free software) and easy-to-use offline browser utility.
Waybackpack - Download the entire Wayback Machine archive for a given URL
SiteSucker - SiteSucker is a Macintosh application that automatically downloads Web sites from the Internet.
ArchiveBox - The open-source, self-hosted internet archiving solution
GNU Wget - GNU Wget is a free software package for retrieving files using HTTP(S) and FTP, the most...
Brunhilde - Analyze YouTube comments to know what your audience thinks