Memento Project
Memento was a project of the United States National Digital Information Infrastructure and Preservation Program (NDIIPP). It was funded with the aim of making Web-archived content more easily discoverable and accessible to the public. The project concluded on 5 September 2025.[1] [2]
Technical description
[edit ]Memento is defined in RFC 7089[3] as an implementation of the time dimension of content negotiation.[4] HTTP accomplishes negotiation of content via a variety of headers that allow clients and servers to find content that the user desires.
| Request Header | Response Header | Dimension | Examples | Reference |
|---|---|---|---|---|
| Accept | Content-Type | content-type of the representation | text/html
text/plain image/png |
RFC 7231[5]
RFC 2616 |
| Accept-Language | Content-Language | language of the representation | en
en-US cz |
RFC 7231
RFC 2616 |
| Accept-Encoding | Content-Encoding | medium, typically compression, that the content has been encoded with | compress
gzip deflate |
RFC 7231
RFC 2616 |
| Accept-Charset | Content -Type | the character set used by the web page | iso-8859-5
unicode-1-1 |
RFC.
7231 RFC 2616 |
| Accept-Datetime | Memento-Datetime | time of the representation | 2014年8月15日 13:43:03
GMT |
RFC 7089 |
The Last-Modified header provided by HTTP[6] does not necessarily reflect when a particular version of a web page came into existence. Also, the Last-Modified header may not exist in some cases. To provide more information, the Memento-Datetime header has been introduced to indicate when a specific representation of a web page was observed on the web.[7]
Usage
[edit ]Copies of page can be found by simply navigating, in a web browser, to a link formatted, replacing urltoarchive with the full URL of the page desired:[8]
JSON description of a Memento:
http://timetravel.mementoweb.org/api/json/YYYY/urltoarchivehttp://timetravel.mementoweb.org/api/json/YYYYMM/urltoarchivehttp://timetravel.mementoweb.org/api/json/YYYYMMDD/urltoarchivehttp://timetravel.mementoweb.org/api/json/YYYYMMDDHH/urltoarchivehttp://timetravel.mementoweb.org/api/json/YYYYMMDDHHMM/urltoarchive- or
redirect to a Memento with a datetime that is close to a desired datetime:
http://timetravel.mementoweb.org/memento/YYYY/urltoarchivehttp://timetravel.mementoweb.org/memento/YYYYMM/urltoarchivehttp://timetravel.mementoweb.org/memento/YYYYMMDD/urltoarchivehttp://timetravel.mementoweb.org/memento/YYYYMMDDHH/urltoarchivehttp://timetravel.mementoweb.org/memento/YYYYMMDDHHMM/urltoarchive
References
[edit ]- ^ Taylor, Nicholas (2025年08月07日). "Memento TimeTravel sunset". memento-dev (Mailing list). Archived from the original on 2025年08月18日. Retrieved 2025年11月21日.
- ^ timetravel.mementoweb.org at the Wayback Machine (archived 2025年09月05日)
- ^ RFC 7089: HTTP Framework for Time-Based Access to Resource States -- Memento
- ^ Berners Lee, Tim. "Web Architecture: Generic Resources". World Wide Web Consortium (W3C). 1996. http://www.w3.org/DesignIssues/Generic Archived 2015年06月02日 at the Wayback Machine
- ^ RFC 7231: Hypertext Transfer Protocol (HTTP/1.1): Semantics and Content
- ^ RFC 7232: Hypertext Transfer Protocol (HTTP/1.1): Conditional Requests
- ^ Nelson, Michael L. "2010-11-05: Memento-Datetime is not Last-Modified". Web Science and Digital Libraries Research Group. November 5, 2010. http://ws-dl.blogspot.com/2010/11/2010-11-05-memento-datetime-is-not-last.html Archived 2015年05月19日 at the Wayback Machine
- ^ "Time Travel APIs". timetravel.mementoweb.org. Archived from the original on 2018年05月21日. Retrieved 2018年05月15日.
External links
[edit ]- Memento Project
- The When of the Web - Extensive information about the proposal and experiment is available in the November 2009 paper
- Memento: Time Travel for the Web
- http://lanlsource.lanl.gov/hello
- http://www.cdlib.org/cdlinfo/2010/02/04/web-archive-discovery-memento-implementation-meeting/