Wayback Machine
Anna's Archive
– Shadow library search engine
archive.today
– Web archive
Heritrix
– Web crawler designed for web archiving
Library Genesis
– File-sharing website for publications
Link rot
– URLs ceasing to function
List of web archiving initiatives
Time capsule
– Historic objects of goods or information
Z-Library
– File-sharing site for journal articles, books, and magazines
https://en.wikipedia.org/wiki/Wayback_Machine