About the Memento Project

Last updated: December 28, 2022

Memento wants to make it as straightforward to access the Web of the past as it is to access the current Web.

With Memento, you are able to access a version of a Web resource as it existed at some date in the past, by entering that resource's HTTP address in your browser like you always do, and by specifying the desired date in a browser plug-in. Obviously, you will only get to see old versions of a resource if some exist, for example, in a web archive or a content versioning system. But if old versions exist, and if they are hosted by servers that support the Memento protocol, you will seamlessly be able to access them. Because most public web archives around the world already support the protocol you can start your web time travel right away by installing the Memento extension for Chrome. One day, hopefully, also browsers will support the protocol and browser extensions will no longer be required.

The Memento protocol is specified in RFC 7089. If you want a more gentle entry point, check out the Introduction to Memento. In essence, the Memento protocol adds a time dimension to HTTP. Inspired by HTTP content negotiation, the protocol introduces the notion of datetime negotiation that allows a client to request a version of a resource as it existed at a specified time in the past. The Memento protocol aligns neatly with a common pattern used for versioning Web resources. Resource Versioning and Memento describes what systems that host resource versions can do to help bootstrap a variety of novel, temporal Web applications.

If you are interested in establishing a Web with a memory, please join the Memento Development Group.

Memento is a collaboration between the Prototyping Team of the Research Library of the Los Alamos National Laboratory and the Computer Science Department of Old Dominion University. Memento has received funding from the Library of Congress and the Andrew W. Mellon Foundation.