I noticed that this website has been mentioned before, but this is either the first time that I've bumped into it or I've just forgotten about it. The most impressive thing about this website is that they do not make it hard to mirror. In fact, they encourage mirroring and make it very easy to do so; even providing instructions on the home page with multiple mirrors, and even an estimate for the total download size!

http://bitsavers.trailing-edge.com/

I wanted to make a new thread about this website, to do my part in raising awareness of this excellent resource.