Raspberry Pi port, piCore-15.0 is available!
Cached links used to live under the drop-down menu next to every search result on Google's page. As the Google web crawler scoured the Internet for new and updated webpages, it would also save a copy of whatever it was seeing. That quickly led to Google having a backup of basically the entire Internet, using what was probably an uncountable number of petabytes of data. Google is in the era of cost savings now, so assuming Google can just start deleting cache data, it can probably free up a lot of resources.