Wayback Machine

The Wayback Machine is a digital time capsule created by the Internet Archive, a non-profit organization, based in San Francisco, California. It is maintained with content from Alexa Internet. The service enables users to see archived versions of web pages across time, which the Archive calls a "three dimensional index".

The name Wayback Machine is a reference to a segment from The Rocky and Bullwinkle Show in which Mr. Peabody and Sherman use a time machine called the "WABAC machine" (pronounced "Wayback") to witness, participate in, and, more often than not, alter famous events in history.

Origins, growth and storage
In 1996, Brewster Kahle, with Bruce Gilliat, developed software to crawl and download all publicly accessible World Wide Web pages, the Gopher hierarchy, the Netnews bulletin board system, and downloadable software. The information collected by these "crawlers" does not collect all the information available on the Internet since much of the data is restricted by the publisher or stored in databases that are not accessible. These "crawlers" also respect the robots exclusion standard for websites wishing to opt-out of appearing in search results or being cached. To overcome inconsistencies in partially cached websites, Archive-It.org was developed in 2005 by the Internet Archive as a means of allowing institutions and content creators to voluntarily harvest and preserve collections of digital content, and create digital archives.

Information was kept on digital tape for five years, with Kahle occasionally allowing researchers and scientists to tap into the clunky database. When the archive reached its five-year anniversary, it was unveiled and opened to the public in a ceremony at the University of California-Berkeley.

Snapshots usually become available more than 6 months after they are archived, or in some cases, even later, 24 months or longer. The frequency of snapshots is variable, so not all tracked web site updates are recorded. Intervals of several weeks or years sometimes occur.

After August 2008 sites had to be listed on the Open Directory in order to be included. According to Jeff Kaplan of the Internet Archive in November 2010, other sites were still being archived, but more recent captures would only become visible after the next major indexing, an infrequent operation.

the Wayback Machine contained approximately three petabytes of data and was growing at a rate of 100 terabytes each month; the growth rate reported in 2003 was 12 terabytes/month. The data is stored on PetaBox rack systems manufactured by Capricorn Technologies.

In 2009 the Internet Archive migrated its customized storage architecture to Sun Open Storage, and hosts a new datacenter in a Sun Modular Datacenter on Sun Microsystems' California campus.

In 2011 a new, improved version of the Wayback Machine, with an updated interface and fresher index of archived content, was made available for public testing.

In March 2011 it was said on the Wayback Machine forum that "The Beta of the new Wayback Machine has a more complete and up-to-date index of all crawled materials into 2010, and will continue to be updated regularly. The index driving the classic Wayback Machine only has a little bit of material past 2008, and no further index updates are planned, as it will be phased out this year."

In January 2013 the company announced a ground-breaking milestone of 240 billion URLs.

Netbula LLC v. Chordiant Software Inc.
In a 2009 case Netbula, LLC v. Chordiant Software Inc., defendant Chordiant filed a motion to compel Netbula to disable the robots.txt file on its web site that was causing the Wayback Machine to retroactively remove access to previous versions of pages it had archived from Nebula's site, pages which Chordiant believed would support its case.

Netbula objected to the motion on the ground that defendants were asking to alter Netbula's web site and that they should have subpoenaed Internet Archive for the pages directly. However, an employee of Internet Archive filed a sworn statement supporting Chordiant's motion, stating that it could not produce the web pages by any other means "without considerable burden, expense and disruption to its operations."

Magistrate Judge Howard Lloyd in the Northern District of California, San Jose Division, rejected Netbula's arguments and ordered them to temporarily disable the robots.txt blockage in order to allow Chordiant to retrieve the archived pages that they sought.

Telewizja Polska
In an October 2004 case, Telewizja Polska USA, Inc. v. Echostar Satellite, No. 02 C 3293, 65 Fed. R. Evid. Serv. 673 (N.D. Ill. Oct. 15, 2004), a litigant attempted to use the Wayback Machine archives as a source of admissible evidence, perhaps for the first time. Telewizja Polska is the provider of TVP Polonia and EchoStar operates the Dish Network. Prior to the trial proceedings, EchoStar indicated that it intended to offer Wayback Machine snapshots as proof of the past content of Telewizja Polska’s website. Telewizja Polska brought a motion in limine to suppress the snapshots on the grounds of hearsay and unauthenticated source, but Magistrate Judge Arlander Keys rejected Telewizja Polska’s assertion of hearsay and denied TVP's motion in limine to exclude the evidence at trial. However, at the actual trial, district Court Judge Ronald Guzman, the trial judge, overruled Magistrate Keys' findings, and held that neither the affidavit of the Internet Archive employee nor the underlying pages (i.e., the Telewizja Polska website) were admissible as evidence. Judge Guzman reasoned that the employee's affidavit contained both hearsay and inconclusive supporting statements, and the purported webpage printouts themselves were not self-authenticating.

Patent law
The United States patent office and the European Patent Office, provided some additional requirements are met (e.g. providing an authoritative statement of the archivist), will accept date stamps from the Internet Archive as evidence of when a given Web page was accessible to the public. These dates are used to determine if a Web page is available as prior art for instance in examining a patent application.

Limitations of utility
There are technical limitations to archiving a website, and as a consequence, it is possible for opposing parties in litigation to misuse the results provided by website archives. This problem can be exacerbated by the practice of submitting screen shots of web pages in complaints, answers or expert witness reports, when the underlying links are not exposed and therefore can contain errors. For example, archives like the Wayback Machine do not fill out forms and therefore do not include the contents of non-RESTful e-commerce databases in their archives.

Legal status
In Europe the Wayback Machine could be interpreted to violate copyright laws. Only the content creator can decide where their content is published or duplicated, so the Archive would have to delete pages from its system upon request of the creator. The exclusion policies for the Wayback Machine can be found in the FAQ section of the site. The Wayback Machine also retroactively respects robots.txt files, i.e. pages which are currently blocked to robots on the live web will be made temporarily unavailable from the archives as well.

A number of cases have been brought against the Internet Archive for its Wayback Machine archiving efforts. See Internet Archive controversies and legal disputes.

Search engine links
In 2005, Yahoo! Search began to provide links to other versions of pages archived on the Wayback Machine.