Good point Chris. Many of these sites are either a one man project to share this information with like minded folks, or a companies commitment to supporting it's products long after they've been discontinued. Don't abuse these resources. It's a good idea to print a copy of any manuals that you need or find a good source for study instead of repeatedly downloading the files. If they ask for donations, throw them $10 or more, just so they know that someone's still interested and that their work isn't going unappreciated.
BTW, for some reason the link in your post wasn't working, but I added it to the Resources sticky and that one's working.
Great find, thanks Chris!