Citizendium ( ; "the citizens' compendium of everything") is an English-language wiki-based free online encyclopedia launched by Larry Sanger, co-founder of Nupedia and Wikipedia.
Sanger had worked as paid staff with Jimmy Wales to make Nupedia and Wikipedia, but left for financial reasons. He had been the editor-in-chief of Nupedia, which had an editorial review process similar to Citizendium's.
It was first announced in September 2006 as a fork of the English Wikipedia,Andrew Orlowski."Wikipedia founder forks Wikipedia, More experts, less fiddling?", The Register, 18 September 2006. In software engineering, a project fork occurs when developers take a copy of source code from one software package and start independent development on it, creating a distinct piece of software. but instead launched in March 2007 with an emphasis on original content. The project's aim was to improve the Wikipedia model by providing increased reliability. It planned to achieve this by requiring virtually all contributors to use their real names, by strictly moderating the project for unprofessional behavior, by providing "gentle expert oversight" of everyday contributors, and through "approved articles" that undergo a form of peer-review by topic experts with credentials.
Active contributors increased through the first quarter of 2008 and then declined; by 27 October 2011, the site had fewer than 100 active members. The last managing editor was Anthony Sebastian, until the office was vacated in 2016. , it had 17,956 "live" and 6,322 "lemma" articles (lemmas are undeveloped articles that contain little more than a definition, similar to stub articles on Wikipedia). , this had changed to 16,440 articles"Welcome to Citizendium", Citizendium. Retrieved 8 September 2025. with an additional 3,744 lemma articles.Category:Lemma Article, Citizendium.Retrieved 8 September 2025.
Founder viewpoints
Sanger said in a 17 October 2006 press release that Citizendium "will soon attempt to unseat Wikipedia as the go-to destination for general information online".Larry Sanger. "Co-Founder to Launch Edited Version of Wikipedia: Pilot Project for the Citizendium to Launch This Week" , Citizendium, 17 October 2006. In August 2007, he captioned its pages: "The world needs a more credible free encyclopedia." The project began its pilot phase in October and November 2006.
On 18 January 2007, a change of plans was announced. Sanger announced on the CZ (Citizendium) mailing list that only articles marked "CZ Live", those which have been or will soon be worked on by Citizendium contributors, would remain on the site, and all other articles forked from Wikipedia would be deleted. Not all Citizendium contributors were supportive of this change, but Sanger emphasized that this deletion was "an experiment" and a new set of Wikipedia articles could be uploaded if the experiment were deemed unsuccessful.Larry Sanger. "OK, let's delete the Wikipedia articles (an experiment)" , Citizendium-l mail list, 18 January 2007.
Planning for succession of editor-in-chief In May 2009, Sanger reduced his direct activity at Citizendium, and, in a message on 30 July 2009, he reminded those on the Citizendium-l mailing list of his previously declared intention not to serve as editor-in-chief for more than two or three years after the start of the project.Larry Sanger [Citizendium-l] My recent absence Sanger has reiterated his call for the Citizendium community to prepare an orderly process for choosing a new editor-in-chief. Sanger said that he was spending more time on his WatchKnow project, partly because he needs to earn an income—he said the "Citizendium project doesn't earn me a dime"—and partly because the Citizendium community had demonstrated that it could function effectively without his close, daily involvement, and because "there are squeakier wheels in my life just now". He added that stepping aside may "precipitate something of a constitutional crisis, considering that we [Citizendium] never adopted a proper charter". Citizendium finally ratified its charter in September 2010. On 22 September 2010, Sanger stepped down as editor-in-chief, but said he would continue to support the project.Larry Sanger blog post, Citizendium blog: Citizendium Charter Ratified
Nature of the project Fork of Wikipedia According to statements and essays on Citizendium, the project was initially intended to begin as a fork of Wikipedia, carrying a copy of each article—under the rules of the GNU Free Documentation License—as it existed on Wikipedia at the time of Citizendium's launch.Larry Sanger. "Why we should fork all at once" , Citizendium-l mail list, 29 September 2006. However, after initiating the idea of not forking, and then soliciting comments on the matter from Citizendium mailing list and web forum members, Sanger said that a complete fork at launch was not a "foregone conclusion".Larry Sanger. "Forking argument summary" , Citizendium forum, 29 September 2006. On 18 January 2007, Sanger announced that the pilot would, as an experiment, only carry articles that had been, or would soon be, worked on by Citizendium contributors, instead of a complete set of Wikipedia articles. He stated that the experiment "represents a reconception of our project's basic aim".
No announcement was made on Citizendium editions in languages other than English, but Sanger stated that they may be forthcoming after the English-language version was established and successfully working. In a review of Andrew Keen's book The Cult of the Amateur, Sanger comments ironically on Keen's favorable treatment of Citizendium: "The first example of a 'solution' he offers is the Citizendium, or the Citizens' Compendium, which I like to describe briefly as Wikipedia with editors and real names. But how can Citizendium be a solution to the problems he raises, if it has experts working without pay, and the result is free? If it succeeds, won't it contribute to the decline of reference publishing?"
Project goal
The stated aim of the project is to create a "new compendium of knowledge" based on the contributions of "intellectuals," defined as "educated, thinking people who read about science or ideas regularly." Citizendium aimed to foster an expert culture and a community that encourages participants (to be called "authors") to "respect" the expert contributions (by what he referred to as a "gentle process of guidance").
Experts are required to verify their qualifications openly, for transparency and publicly accepted authority. This contrasts with the open and largely anonymous nature of Wikipedia, where subject specialists have neither any verifiable special knowledge of their subject nor agreed special status. Sanger stated that editors would not have pre-approval rights over edits by ordinary authors, though editors would have somewhat undefined authority over articles that fall within their specific area of expertise.
Policies and structure Unlike Wikipedia, Citizendium does not allow anonymous editing. Participants must register under their real names with a working email address. Sanger decided that Citizendium administrators would be called "constables," and need a bachelor's degree to qualify. He also instituted a minimum "maturity" requirement—25 years of age—for constables. The "head" constable is the Chief Constable (D. Matt Innis), and the head editor is the Managing Editor.Larry Sanger. "Constables, editors, and the Citizendium Foundation" , Citizendium-l mail list, 23 September 2006.
Originally, Sanger operated as Editor-in-Chief, the "main individual in charge," part of and answerable to a Board of Directors. Sanger stated that final decisions about management structure will not be made "until more of the (future) primary stakeholders are on the scene."Larry Sanger. "How should we manage growth?" , Citizendium forum, 2 October 2006.
Citizendium articles are subject to an "approval" process after they have achieved reasonable quality. An "editor" can determine when an article is ready to be approved.
Initially the project phased under the Tides Center as an incubator project and then was supposed to be carried out under the auspices of the Citizendium Foundation, but in 2020, the treasurer of the project stated that the foundation was never registered.
Content
Citizendium original articles are available under the Creative Commons Attribution ShareAlike 3.0 Unported License (CC BY-SA). Articles that originated in part from Wikipedia are also available under the GNU Free Documentation License version 1.2. These licensing decisions were announced on 21 December 2007, about a year after the launch of the pilot project.
History
Pilot project and initial growth The project was announced by Sanger on 15 September 2006, at the Wizards of OS 4 conference in Berlin. He gave no deadline for the full launch of the wiki.Larry Sanger. "Citizendium launch plan as of 26 September" , Citizendium-l mail list, 27 September 2006.WOS video stream containing Sanger's announcement However, on 2 October 2006, Sanger released a pilot project announcement that envisioned a fully functioning wiki within "one to two months."
In an apparent attempt to quicken the pace of the project, on 2 October 2006, Citizendium web forum moderator Peter Hitchmough suggested what he called an "alpha test" of the concept. Hitchmough proposed the forking of a limited number of Wikipedia articles to a site where Citizendium web forum and mailing list members could "rewrite a complete section" of Wikipedia content.Peter Hitchmough. "Proposal: Fork Wikipedia and launch with some A1-class model subjects" , Citizendium forum, 2 October 2006.
Larry Sanger reacted enthusiastically to the idea and at first suggested his already existing Textop wiki as the site for the alpha test. Sanger later posted that Textop would not be a good choice, but showed continued interest in the proposal. He envisioned a "restricted-access" wiki where the idea could be tried and requested further discussion.Larry Sanger. "Administrivia: interesting pilot project proposal" , Citizendium-l mail list, 2 October 2006.
No access to the pilot version of Citizendium, even read-only, was allowed to the general public. Sanger stated: "Only invited people will be able to view and edit the pilot project wiki."Larry Sanger. "Call for applications to participate in the Citizendium Pilot Project" , Citizendium. Sanger also said that constables for the pilot project will be chosen by the chief constable.Larry Sanger. "Pilot Project Application Review Procedure" , Citizendium-l mail list, 13 November 2006.
In a press release on 17 October 2006, Sanger announced: "the fledgling Citizendium Foundation will launch a six-week pilot project open to potential contributors by invitation". Several editors and other project leaders were named. It was also announced that the Citizendium Foundation had "started the process of applying for 501(c)(3) status [non-profit status]" and had "received a firm commitment for a significant seed grant from a foundation, as well as small personal donations." In a follow-up post to the press release, Sanger said that the initial group allowed access to the pilot would consist of "ten editors, three constables, six authors, and me."Larry Sanger. "Ad hoc steering group kicked off" , Citizendium-l mail list, 18 October 2006.
The pilot project began operations on 23 October 2006.Jason Potkanski. "Developers Wanted: forge.citizendium.org Open" , Citizendium-l mail list, 23 October 2006. On 8 November, Larry Sanger reported that 263 user names had access to the pilot wiki, 183 articles on the wiki were "live" (meaning "someone is or intends to be working on them") and there were about 300 total edits to the wiki on 7 November.Larry Sanger. "Stats" , Citizendium blog, 8 November 2006.