Archive.org, a nonprofit digital library that curates web pages, has announced extensions for the Google Chrome and Mozilla Firefox web browsers. The organization's Internet Archives (or Wayback Machine, as it's commonly known) indexes more than 400 million deleted websites and makes them publicly available. To access iterations of old or removed websites, users had to visit Archive.org directly. But Chrome and Firefox will now automatically invite users to view the file when they hit a deprecated URL, as long as the extension is installed.