HTTrack is an easy-to-use offline browser utility. It allows you to download a
World Wide website from the Internet to a local directory, building recursively
all directories, getting html, images, and other files from the server to your
computer. HTTrack arranges the original site's relative link-structure. Simply
open a page of the "mirrored" website in your browser, and you can browse the
site from link to link, as if you were viewing it online.

HTTrack can also update an existing mirrored site, and resume interrupted
downloads. HTTrack is fully configurable, and has an integrated help system.

See also: https://github.com/xroche/httrack