Soon, 'time-travelling' browsing technology to navigate web's past

Albuquerque Express (ANI) Tuesday 17th November, 2009

London, Nov 17 : A 'time-travelling' web browsing technology is being pioneered at the Los Alamos National Laboratory in New Mexico to make it simpler to find old versions of web pages.

Called Memento, the system Herbert Van de Sompel, a computer scientist at Los Alamos, is developing alongside colleagues from Old Dominion University in Norfolk, Virginia, gives browsers a "time-travel" mode, allowing users to find web pages from particular dates and times without having to navigate through archives.

The system harnesses a function of the hypertext transfer protocol (HTTP) - the system which underpins the world wide web by defining how web pages are formatted and transmitted from servers to browsers.

One of HTTP's standard functions is called content negotiation. This allows one URL to send multiple types of data, depending on the settings of the browser that contacts the URL.

For example, a browser in France accessing a URL may retrieve an HTML page in French, while accessing the same URL from the US may deliver an English version.

"Your browser does this negotiation all the time, but you don't notice it," New Scientist quoted de Sompel as saying.

However, HTTP content negotiation is not limited to arbitrating between media formats and languages - it can cope with any data type. So the team are adding another dimension to page requests: date and time.

"In addition to language and media type, we negotiate in time. So Memento asks the server not for today's version of this page, but how it looked one year ago, for instance," de Sompel said.

Memento comprises both server and browser software. On a server running the open-source Apache web system, just four lines of extra code are needed to build in date-and-time negotiation. On the browser, a drop-down menu will let users enter the date and time for which they want to view a page.

So far, the researchers have developed a Memento plug-in for the open-source Firefox browser, plus a "hacked" version of Firefox with built-in Memento capability.

Web pages need no extra features: the web server just needs to intercept the date-time requests of users. A demonstration of what Memento can do is available for any browser.

Of course, the whole idea requires website owners to store many more time-stamped versions of their pages than they do now, but the team think Memento will encourage them to do this.

"I would love to see Memento supported. It would be such fun to set our browsers back in time and just browse the past," de Sompel said.