I don't really know what to do with this yet but figured someone here may find a use for it in the meantime.
If you know the URI of a Web resource, the technical framework proposed by Memento allows you to see a version of that resource as it existed at some date in the past, by entering that URI in your browser like you always do and by specifying the desired date in a browser plug-in. Or you can actually browse the Web of the past by selecting a date and clicking away. Whatever you land upon will be versions of Web resources as they were around the selected date. Obviously, this will only work if previous versions are available somewhere on the Web. But if they are, and if they are on servers that support the Memento framework, you will get to them.
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 team has 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 here:
http://www.mementoweb.org/demo/
