DMOZ screenshot = url =dmoz.org slogan = Open
Directory Project commercial = No type =
registration = Optional language = 90 languages, including English
num_users = 90,000 content_license =
Open Directory License ,
Creative Commons Attribution
Creative Commons Attribution 3.0 Unported owner =
Verizon Communications ) launch_date = June 5, 1998; 19 years ago
(1998-06-05) alexa = 64,731 (July 2017 ) current_status = Closed
content license =
Creative Commons Attribution
Creative Commons Attribution 3.0 Unported, Open
Directory License }}
DMOZ (from directory.mozilla.org, an earlier domain name ) was a
multilingual open-content directory of
World Wide Web
World Wide Web links. The site
and community who maintained it were also known as the OPEN DIRECTORY
PROJECT (ODP). It was owned by
AOL but constructed and maintained by a
community of volunteer editors.
DMOZ used a hierarchical ontology scheme for organizing site
listings. Listings on a similar topic were grouped into categories
which then included smaller categories.
DMOZ closed on March 17, 2017 because
AOL no longer wished to support
the project. The website became a single landing page on that day,
with links to a static archive of DMOZ, and to the
forum, where plans to rebrand and relaunch the directory are being
* 1 History
* 1.1 System failure and editing outage, October to December 2006
* 1.2 Competing and spinoff projects
* 1.3 Logotypes
* 2 Content
* 2.1 Maintenance
* 2.2 License and requirements
* 2.3 RDF dumps
* 2.4 Content users
* 3 Policies and procedures
* 4 Controversy and criticism
* 4.1 Ownership and management
* 4.2 Editor removal procedures
* 4.3 Allegations that editors are removed for criticizing policies
* 4.4 Blacklisting allegations
* 5 Software
* 5.1 Search
* 5.2 Editor forums
* 5.3 Bug tracking
* 5.4 Interface
* 6 See also
* 7 References
* 8 External links
DMOZ was founded in the United States as GNUHOO by
Rich Skrenta and
Bob Truel in 1998 while they were both working as engineers for Sun
Microsystems . Chris Tolles, who worked at
Sun Microsystems as the
head of marketing for network security products, also signed on in
1998 as a co-founder of Gnuhoo along with co-founders Bryn Dole and
Jeremy Wenokur. Skrenta had developed TASS , an ancestor of tin , the
Usenet newsreader for
Unix systems. The original
category structure of the Gnuhoo directory was based loosely on the
Usenet newsgroups then in existence.
The Gnuhoo directory went live on June 5, 1998. After a Slashdot
article suggested that Gnuhoo had nothing in common with the spirit of
free software , for which the
GNU project was known, Richard Stallman
Free Software Foundation objected to the use of "Gnu" in the
name and Gnuhoo was changed to NewHoo.
Yahoo! then objected to the use
of "Hoo" in the name, prompting a proposed name change, to ZURL.
Prior to switching to ZURL, NewHoo was acquired by Netscape
Communications Corporation in October 1998 and became the Open
Netscape released Open Directory data under the
Open Directory License .
Netscape was acquired by
DMOZ was one of the assets included in the acquisition.
DMOZ size by date, 1998 to 2015.
By the time
Netscape assumed stewardship, the Open Directory Project
had about 100,000 URLs indexed with contributions from about 4500
editors. On October 5, 1999, the number of URLs indexed by DMOZ
reached one million. According to an unofficial estimate, the URLs in
DMOZ numbered 1.6 million in April 2000, surpassing those in the
Yahoo! Directory .
DMOZ achieved the milestones of indexing two
million URLs on August 14, 2000, three million listings on November
18, 2001 and four million on December 3, 2003. As of April, 2013 there
were 5,169,995 sites listed in over 1,017,500 categories. On October
31, 2015, there were 3,996,412 sites listed in 1,026,706 categories.
In January 2006,
DMOZ began publishing online reports to inform the
public about the development of the project. The first report covered
the year 2005. Monthly reports were issued subsequently until
September 2006. These reports gave greater insight into the
functioning of the directory than the simplified statistics provided
on the front page of the directory. The number of listings and
categories cited on the front page included "Test" and "Bookmarks"
categories but these were not included in the RDF dump offered to
users. There were about 7330 active editors during August 2006.
75,151 editors had contributed to the directory as of March 31, 2007.
As of April 2013, the number of contributing editors had increased to
SYSTEM FAILURE AND EDITING OUTAGE, OCTOBER TO DECEMBER 2006
On October 20, 2006, DMOZ's main server suffered a catastrophic
failure that prevented editors from working on the directory until
December 18, 2006. During that period, an older build of the directory
was visible to the public. On January 13, 2007, the Site Suggestion
and Update Listings forms were again made available. On January 26,
2007, weekly publication of RDF dumps resumed. To avoid future
outages, the system resided on a redundant configuration of two
Intel-based servers from then on.
The site's interface was given an upgrade in 2016, branded "
AOL took it offline the following year.
COMPETING AND SPINOFF PROJECTS
DMOZ became more widely known, two other major web directories
edited by volunteers and sponsored by
Go.com and Zeal emerged, both
now defunct. These directories did not license their content for open
The concept of using a large-scale community of editors to compile
online content has been successfully applied to other types of
projects. DMOZ's editing model directly inspired at least three other
open content volunteer projects: music site MusicMoz, an open content
restaurant directory known as
ChefMoz and an encyclopedia known as
Open Site . Finally, according to
Larry Sanger ,
DMOZ was part of the
inspiration for the
Nupedia project, out of which grew.
Original logo as from June 1998
Logo after rebranding as NewHoo
Logo after acquisition by
Logo from 1999 to 2014 with the name
Logo from March 2014
Logo from June 2016 until the closing in March 2017
DMOZ front page, January 2006
Gnuhoo borrowed the basic outline for its initial ontology from
Usenet . In 1998,
Rich Skrenta said, "I took a long list of groups and
hand-edited them into a hierarchy." For example, the topic covered by
the comp.ai.alife newsgroup was represented by the category
Computers/AI/Artificial_Life. The original divisions were for Adult,
Arts, Business, Computers, Games, Health, Home, News, Recreation,
Reference, Regional, Science, Shopping, Society, Sports and "World".
While these sixteen top-level categories have remained intact, the
ontology of second- and lower-level categories has undergone a gradual
evolution; significant changes are initiated by discussion among
editors and then implemented when consensus has been reached.
In July 1998, the directory became multilingual with the addition of
the World top-level category. The remainder of the directory lists
only English language sites. By May 2005, seventy-five languages were
represented. The growth rate of the non-English components of the
directory has been greater than the English component since 2002.
While the English component of the directory held almost 75% of the
sites in 2003, the World level grew to over 1.5 million sites as of
May 2005, forming roughly one-third of the directory. The ontology in
non-English categories generally mirrors that of the English
directory, although exceptions which reflect language differences are
Several of the top-level categories have unique characteristics. The
Adult category is not present on the directory homepage but it is
fully available in the RDF dump that
DMOZ provides. While the bulk of
the directory is categorized primarily by topic, the Regional category
is categorized primarily by region. This has led many to view
two parallel directories: Regional and Topical.
On November 14, 2000, a special directory within
DMOZ was created for
people under 18 years of age. Key factors distinguishing this "Kids
and Teens" area from the main directory are:
* stricter guidelines which limit the listing of sites to those
which are targeted or "appropriate" for people under 18 years of age;
* category names as well as site descriptions use vocabulary which
is "age appropriate ";
* age tags on each listing distinguish content appropriate for kids
(age 12 and under), teens (13 to 15 years old) and mature teens (16 to
18 years old);
* Kids and Teens content is available as a separate RDF dump;
* editing permissions are such that the community is parallel to
that of DMOZ.
By May 2005, this portion of
DMOZ included over 32,000 site listings.
Since early 2004, the whole site has been in
UTF-8 encoding. Prior to
this, the encoding used to be
ISO 8859-1 for English language
categories and a language-dependent character set for other languages.
The RDF dumps have been encoded in
UTF-8 since early 2000.
Directory listings are maintained by editors. While some editors
focus on the addition of new listings, others focus on maintaining the
existing listings and some do both. This includes tasks such as the
editing of individual listings to correct spelling and/or grammatical
errors, as well as monitoring the status of linked sites. Still others
go through site submissions to remove spam and duplicate submissions.
Robozilla is a
Web crawler written to check the status of all sites
listed in DMOZ. Periodically, Robozilla will flag sites which appear
to have moved or disappeared and editors follow up to check the sites
and take action. This process is critical for the directory in
striving to achieve one of its founding goals: to reduce the link rot
in web directories. Shortly after each run, the sites marked with
errors are automatically moved to the unreviewed queue where editors
may investigate them when time permits.
Due to the popularity of
DMOZ and its resulting impact on search
engine rankings (See
PageRank ), domains with lapsed registration that
are listed on
DMOZ have attracted domain hijacking , an issue that has
been addressed by regularly removing expired domains from the
While corporate funding and staff for
DMOZ have diminished in recent
years, volunteers have created editing tools such as linkcheckers to
supplement Robozilla, category crawlers, spellcheckers, search tools
that directly sift a recent RDF dump, bookmarklets to help automate
some editing functions, mozilla based add-ons, and tools to help work
through unreviewed queues.
LICENSE AND REQUIREMENTS
DMOZ data was previously made available under the terms of the Open
Directory License , which required a specific
DMOZ attribution table
on every Web page that uses the data.
Open Directory License also included a requirement that users of
the data continually check
DMOZ site for updates and discontinue use
and distribution of the data or works derived from the data once an
update occurs. This restriction prompted the Free Software Foundation
to refer to the
Open Directory License as a non-free documentation
license, citing the right to redistribute a given version not being
permanent and the requirement to check for changes to the license.
DMOZ silently changed its license to a Creative Commons
Attribution license, which is compatible with the FSF.
DMOZ data is made available through an RDF-like dump that is
published on a download server, older versions are also archived
there. New versions are usually generated weekly. An
DMOZ editor has
catalogued a number of bugs that are encountered in the
DMOZ RDF dump,
most importantly that the file format isn't RDF. So while today the
so-called RDF dump is valid
XML , it is not valid RDF and as such,
software to process the
DMOZ RDF dump needs to be specifically written
DMOZ data powers the core directory services for many of the Web's
largest search engines and portals, including
Netscape Search, AOL
Search, and Alexa .
Google Directory used
DMOZ information, until
being shuttered in July 2011.
Other uses are also made of
DMOZ data. For example, in the spring of
2004 Overture announced a search service for third parties combining
Yahoo! Directory search results with
DMOZ titles, descriptions and
category metadata. The search engine
Gigablast announced on May 12,
2005 its searchable copy of DMOZ. The technology permits search of
websites listed in specific categories, "in effect, instantly creating
over 500,000 vertical search engines".
As of 8 September 2006 ,
DMOZ listed 313 English-language Web sites
DMOZ data as well as 238 sites in other languages. However,
these figures do not reflect the full picture of use, as those sites
DMOZ data without following the terms of the
DMOZ license are
POLICIES AND PROCEDURES
DMOZ was co-founded by
Rich Skrenta (depicted in 2009, age 42).
Restrictions are imposed on who can become an
DMOZ editor. The
primary gatekeeping mechanism is an editor application process wherein
editor candidates demonstrate their editing abilities, disclose
affiliations that might pose a conflict of interest , and otherwise
give a sense of how the applicant would likely mesh with the DMOZ
culture and mission. A majority of applications are rejected but
reapplying is allowed and sometimes encouraged. The same standards
apply to editors of all categories and subcategories.
DMOZ's editing model is a hierarchical one. Upon becoming editors,
individuals will generally have editing permissions in only a small
category. Once they have demonstrated basic editing skills in
compliance with the Editing Guidelines, they are welcome to apply for
additional editing privileges in either a broader category or else
another category in the directory. Mentorship relationships between
editors are encouraged, and internal forums provide a vehicle for new
editors to ask questions.
DMOZ has its own internal forums, the contents of which are intended
only for editors to communicate with each other primarily about
editing topics. Access to the forums requires an editor account and
editors are expected to keep the contents of these forums private.
Over time, senior editors can be granted additional privileges which
reflect their editing experience and leadership within the editing
community. The most straightforward are editall privileges, which
allow an editor to access all categories in the directory. Meta
privileges additionally allow editors to perform tasks such as
reviewing editor applications, setting category features, and handling
external and internal abuse reports. Cateditall privileges are similar
to editall, but only for a single directory category. Similarly,
catmod privileges are similar to meta, but only for a single directory
category. Catmv privileges allow editors to make changes to directory
ontology by moving or renaming categories. All of these privileges are
granted by admins and staff, usually after discussion with meta
In August 2004, a new level of privileges called admin was
introduced. Administrator status was granted to a number of long
serving metas by staff. Administrators have the ability to grant
editall+ privileges to other editors and to approve new directory-wide
policies, powers which had previously only been available to root
DMOZ editors are expected to abide by DMOZ's Editing Guidelines.
These guidelines describe editing basics: which types of sites may be
listed and which may not; how site listings should be titled and
described in a loosely consistent manner; conventions for the naming
and building of categories; conflict of interest limitations on the
editing of sites which the editor may own or otherwise be affiliated
with; and a code of conduct within the community. Editors who are
found to have violated these guidelines may be contacted by staff or
senior editors, have their editing permissions cut back, or lose their
editing privileges entirely.
DMOZ Guidelines are periodically revised
after discussion in editor forums.
CONTROVERSY AND CRITICISM
There have long been allegations that volunteer
DMOZ editors give
favorable treatment to their own websites while concomitantly
thwarting the good faith efforts of their competition. Such
allegations are fielded by ODP's staff and meta editors, who have the
authority to take disciplinary action against volunteer editors who
are suspected of engaging in abusive editing practices. In 2003, DMOZ
introduced a new Public Abuse Report System that allows members of the
general public to report and track allegations of abusive editor
conduct using an online form. Uninhibited discussion of DMOZ's
purported shortcomings has become more common on mainstream Webmaster
discussion forums. Although site policies suggest that an individual
site should be submitted to only one category, as of October 2007,
Topix.com, a news aggregation site operated by
DMOZ founder Rich
Skrenta, had more than 17,000 listings.
Early in the history of DMOZ, its staff gave representatives of
selected companies, such as
Rolling Stone or
CNN , editing access in
order to list individual pages from their websites. Links to
CNN articles were added until 2004, but were entirely
removed from the directory in January 2008 due to the content being
outdated and not considered worth the effort to maintain. There have
been no similar experiments with the editing policy since then.
OWNERSHIP AND MANAGEMENT
Underlying some controversy surrounding
DMOZ is its ownership and
management. Some of the original GnuHoo volunteers felt that they had
been deceived into joining a commercial enterprise. To varying
degrees, those complaints have continued up until the present.
At DMOZ's inception, there was little thought given to the idea of
DMOZ should be managed and there were no official forums ,
guidelines or FAQs . In essence,
DMOZ began as a free for all.
As time went on, the ODP Editor Forums became the de facto DMOZ
parliament and when one of DMOZ's staff members would post an opinion
in the forums, it would be considered an official ruling. Even so,
DMOZ staff began to give trusted senior editors additional editing
privileges, including the ability to approve new editor applications,
which eventually led to a stratified hierarchy of duties and
DMOZ editors, with DMOZ's paid staff having the final
say regarding DMOZ's policies and procedures. Screenshot taken
on April 2017 showing
DMOZ website to be closed.
Robert Keating, a principal of Touchstone Consulting Group in
Washington, D.C. since 2006, has worked as AOL's Program Manager for
DMOZ since 2004. He started working for
AOL in 1999 as Senior Editor
AOL Search, then as Managing Editor,
AOL Search, DMOZ, and then as
Media Ecosystem Manager,
AOL Product Marketing.
EDITOR REMOVAL PROCEDURES
DMOZ's editor removal procedures are overseen by DMOZ's staff and
meta editors. According to DMOZ's official editorial guidelines,
editors are removed for abusive editing practices or uncivil
behaviour. Discussions that may result in disciplinary action against
volunteer editors take place in a private forum which can only be
accessed by DMOZ's staff and meta editors. Volunteer editors who are
being discussed are not given notice that such proceedings are taking
place. Some people find this arrangement distasteful, wanting instead
a discussion modelled more like a trial held in the U.S. judicial
In the article "Editor Removal Explained",
DMOZ meta editor Arlarson
states that "a great deal of confusion about the removal of editors
DMOZ results from false or misleading statements by former
The DMOZ's confidentiality guidelines prohibit any current DMOZ
editors in a position to know anything from discussing the reasons for
specific editor removals. However, a generic list of reasons is for
example given in the guidelines. In the past, this has led to removed
DMOZ editors wondering why they cannot login at
DMOZ to perform their
ALLEGATIONS THAT EDITORS ARE REMOVED FOR CRITICIZING POLICIES
David F. Prenatt, Jr., former
DMOZ editor netesq, and another former
editor known by the alias The Cunctator, both claim to have been
removed for disagreeing with staff about changes to policies,
particularly DMOZ's copyright policies. According to their claims,
staff use the excuse of uncivil behaviour as a means to remove
DMOZ editors have the ability to attach "warning" or "do not
list" notes to individual domains but no editor has the unilateral
ability to block certain sites from being listed. Sites with these
notes might still be listed and at times notes are removed after some
Criticism of DMOZ's hierarchical structure emerged by around 2005.
Many believe hierarchical directories are too complicated. With the
Web 2.0 , folksonomies began to appear, and some editors
proposed that folksonomies, networks and directed graphs are more
"natural" and easier to manage than hierarchies.
The ODPSearch software is a derivative version of
Isearch which is
open source , licensed under the
Mozilla Public License .
The ODP Editor Forums were originally run on software that was based
on the proprietary Ultimate Bulletin Board system. In June 2003, they
switched to the open source phpBB system. As of 2007, these forums are
powered by a modified version of phpBB.
The bug tracking software used by the ODP is
Bugzilla and the web
server Apache . Squid web proxy server was also used but it was
removed in August 2007 when the storage servers were reorganized. All
these applications are open source.
DMOZ database/editing software is closed source (although Richard
Skrenta has said in June 1998 that he was considering licensing it
GNU General Public License ). This has led to criticism from
GNU project, many of whom also criticized the DMOZ
content license. The content was later released under a Creative
Commons license, which is compatible with the
As such, there have been some efforts to provide alternatives to
DMOZ. These alternatives would allow communities of like-minded
editors to set up and maintain their own open source/open content Web
directories. However, no significant open source/open content
DMOZ has emerged.
* Internet portal
List of web directories
* ^ "dmoz.org Traffic Statistics".
Alexa Internet . Retrieved
* ^ Sullivan, Danny (March 17, 2017). "
DMOZ has officially closed
after nearly 19 years of humans trying to organize the web". Search
Engine Land . Retrieved July 17, 2017.
* ^ A B "Why Dmoz Was Closed ?". Resource-Zone.com. 2017-04-16.
* ^ A B "The GnuHoo BooBoo".
Slashdot . Retrieved April 27, 2007.
* ^ "Zurl Directory" Archived December 23, 2007, at the Wayback
* ^ ODP and Yahoo Size Charts by ODP editor geniac
* ^ A B ODP reports by ODP volunteer administrator chris2001
* ^ A B ODP Front Page. Retrieved August 15, 2006
* ^ "Dmoz\'s Catastrophic Server/Hardware Failure".
dmozgrunt.blogspot.com. October 27, 2006. Retrieved July 17, 2017.
* ^ dmoz.org technical problems archive.li Retrieved July 17, 2017.
* ^ The Hamsters\' New Home, in: Open Directory newsletter issue
Winter 2006. Retrieved December 26, 2006.
* ^ "GO Network Terms of Service and Conditions of Use" Archived
May 10, 2000, at the
Wayback Machine .
ChefMoz Fine Dining Menu, in: Open Directory newsletter issue
* ^ help on open-site.org
* ^ Moody, Glyn (July 13, 2006). "This time, it\'ll be a
written by experts".
The Guardian . Retrieved July 17, 2017.
* ^ Sullivan, Danny (July 1, 1998). "NewHoo: Yahoo Built By The
Search Engine Watch
Search Engine Watch . Retrieved July 17, 2017.
* ^ Kids and Teens Launches! Open Directory Project Newsletter,
* ^ "Kids&Teens Guidelines". Dmoz.org. Retrieved 2014-06-18.
* ^ "ODPExtension"
Mozilla based add-on, ODP Magic.. formerly known
as ODP Extension
* ^ Gnu Project: Non-Free Documentation Licenses
* ^ "Open Directory RDF Dump". Rdf.dmoz.org. Retrieved 2014-06-18.
* ^ "ODP/dmoz Data Dump ToDo List". steevithak.com. Retrieved July
* ^ "Google Streamlining: Say Goodbye to the
Google Directory and
Labs!". Pandia Search Engine News. July 21, 2011. Retrieved July 25,
* ^ "
Gigablast Launches 500,000 Vertical Search Engines". Gigablast
. May 12, 2005. Retrieved July 17, 2017.
* ^ Category: Sites Using ODP Data on www.dmoz.org. Retrieved
September 8, 2006.
* ^ "Become an Editor at the Open Directory Project". Dmoz.org.
* ^ A B "ODP Communication Guidelines". Dmoz.org. Retrieved
* ^ A B "Open Directory Project Administrator Guidelines".
Dmoz.org. Retrieved 2014-06-18.
* ^ "ODP Directory Editorial Guidelines". Dmoz.org. Retrieved
* ^ "How To: ODP Editor Is Competitor". webmasterworld.com.
November 4, 2000. Retrieved July 17, 2017.
* ^ ODP Meta Guidelines: Editor Abuse and Removal. Retrieved
October 9, 2008.
* ^ "Open Directory Project: Public Abuse Report System".
Report-abuse.dmoz.org. Retrieved 2014-06-18.
* ^ "How to suggest a site to the Open Directory". Dmoz.org.
* ^ Open Directory Project Search: "topix" (Retrieved October 18,
* ^ "Multiple URL\'s in DMOZ". webmasterworld.com. January 30,
2003. Retrieved July 17, 2017.
* ^ http://www.dmoz.org/News/, taken from Archive.org
* ^ "The Open Directory Project: The Spirit of the Web".
laisha.com. Retrieved July 17, 2017.
* ^ A B C "Open Directory Project Meta Guidelines". dmoz.org.
December 31, 2013. Archived from the original on March 4, 2017.
Retrieved July 21, 2017.
* ^ Meet AOL\'s
DMOZ Staff Team,
DMOZ Blog, January 8, 2009
* ^ Robert Keating LinkedIn
* ^ A B Prenatt, David (May 29, 2000). "Life After ODP". Yahoo!
Groups . Retrieved July 17, 2017.
* ^ Arlarson, Editor Removal Explained, Open Directory Project
Newsletter (September 2000).
* ^ "Guidelines: Account Removal". dmoz.org. 2016-07-03. Archived
from the original on 2017-03-17. Retrieved 2017-07-21.
* ^ "Editor account expired". resource-zone.com. July 27, 2004.
Retrieved July 17, 2017.
* ^ Thread: Can\'t Login on Resource-Zone
* ^ Prenatt, Jr, David F. (June 1, 2000). "Life After the Open
Directory Project". traffick.com. Retrieved July 17, 2017.
* ^ CmdrTaco (October 24, 2000). "Dmoz (aka AOL) Changing
Guidelines In Sketchy Way".
Slashdot . Retrieved July 17, 2017.
* ^ Add Note to URL Feature, in ODP Documentation
* ^ Hriţcu, C. (April 8, 2005). "Folksonomies vs. Ontologies".
hritcu.wordpress.com. Retrieved July 17, 2017.
* ^ "Ontology is Overrated" Archived July 29, 2013, at the Wayback
* ^ Hammond, Tony; Hannay, Timo; Lund, Ben; Scott, Joanna (April
2005). "Social Bookmarking Tools (I)".
D-Lib Magazine . Retrieved July
* ^ "Open Directory Search Guide". Dmoz.org. Retrieved 2014-06-18.
* ^ "Licenses for Works of Practical Use besides Software and
GNU Project . Retrieved July 17, 2017.