Website: Wayback Machine

The Wayback Machine is a section of the Internet Archive. What makes this website so notable is that, while the Internet Archive is, well, an archive of the Internet, the Wayback Machine allows people to actually access past versions of web pages.

In other words, it's the browser version of a Time Machine.

Here's how it works: after accessing the WM website through the link at the top of this page, users can paste a URL address on the input-box next to the "Take Me Back" button, and then, after clicking said button, the user is shown a calendar-like list of archived pages (provided there are any). Dates written on blue dots are links to versions of that particular page archived on that particular date.

It's not 100% reliable - very often the particular page or image you remember most fondly will turn out to be missing from the Wayback archive. The site also follows the Robots exclusion standard, so if your favorite website blocks the Wayback Machine from archiving it in its robots.txt file, then it and its content can become Lost Forever.

This site is recommended to everyone who feels nostalgic about certain sites prior to unwanted changes.

However, that very same kind of feeling is mirrored by part of TV Tropes' community as well, so, for every troper who has never witnessed certain articles prior to deletion of either examples or whole articles themselves, this link leads to the results for the TV Tropes Main Page in the Wayback Machine; changing the URL posted to that of either existing articles or Permanent Red Link Club members, they can access most of the site as it used to be. It's also a good way to show (and not tell) exactly why certain articles are now perma-redlinked.

By the way, it gets its name after the WABAC time machine from Peabody's Improbable History. And now you know.