Show HN: Archive websites from the command line (github.com)

Cool.

How does it work? What's under hood?

At first glance I love this, looking forward to putting it through its paces. I often use wget to backup local copies of websites and it's been frustrating having no easy/automatic system to (a) keep easy information about when the snapshot was taken and (b) allows me to incrementally relate that snapshot into a network of historical info