Demos of the Memento "Time Travel for the Web" Protocol

The Memento protocol could natively be supported by web browsers. Since all major web archives support it, and given the increased interest in using those archives as a means of tracing back original versions of published web pages, that would actually be quite beneficial. But, thus far, that's not happened. Browser extension were developed for both Chrome and FireFox but, lacking resources for maintenance, they've meanwhile been discontinued. Fortunately, there's this 2013 movie that illustrates the power of using the Memento protocol for time traveling the web using an off-the-shelf browser:

The Memento protocol can also be supported by resource versioning systems such as wikis. This flip book movie is a fun illustration of what that enables, in addition to time traveling such systems using a Memento-enabled browser.

This is how the movie was created:

• For months, subtly changing "pictures of the day" were published that depict a member of the Memento team posing next to a flip chart. The changes are in the shirts worn, the timestamps, and the BBC content superimposed on the flip chart.
• At any moment in time, the current picture of the day was served from the URI http://lanlsource.lanl.gov/pics/picoftheday.png.
• On a daily basis, these images were archived using a transactional archive approach. As a result, old versions of these pictures become available at URIs like http://mementoarchive.lanl.gov/ta/20100320180023/http://lanlsource.lanl.gov/pics/picoftheday.png
• Using the following script that targets the generic URI of a picture of the day (http://lanlsource.lanl.gov/pics/picoftheday.png) with incrementing datetime values for HTTP content negotiation and "follow your nose" HTTP navigation, all pictures of the day were automatically collected. In essence, the URI is asked about its past, and the URI gracefully responds by pointing at a TimeGate that knows about its past, and redirects to archived images that match the requested datetime values.
  
  #!/usr/bin/python import os, sys, urllib2 from datetime import datetime, timedelta fmtstr = "%a, %d %b %Y %H:%M:%S GMT" img = "http://lanlsource.lanl.gov/pics/picoftheday.png" timegate = "http://mementoarchive.lanl.gov/store/ta/timegate/" first = datetime.strptime("Mon, 30 Sep 2009 19:00:00", fmtstr[:-4]) (now, td) = (datetime.now(), timedelta(1)) (savePath, typ) = ('/path/to/save', 'png') def get_memento(t): req = urllib2.Request(timegate + img) req.add_header('Accept-Datetime', t.strftime(fmtstr)) fh = urllib2.urlopen(req) data = fh.read() when = fh.headers.dict.get('memento-datetime', '') dt = datetime.strptime(when, fmtstr) if when else None fh.close() return (dt, data) def iterate(): (t, i, odt) = (first, 1, None) while t < now: (dt, data) = get_memento(t) if dt != odt: fn = os.path.join(savePath, "%04d.%s" % (i, typ)) fh = file(fn, 'w') fh.write(data) ; fh.close() odt = dt ; t += td ; i += 1 sys.stdout.write('.') ; sys.stdout.flush() iterate()
  
  
• The collected pictures were then concatenated to obtain the above flip book movie.