This month, Wikipedia officially celebrates 15 years as the internet's free encyclopedia, cataloguing humankind's achievements in real time and, more importantly, rescuing desperate students facing assignment deadlines. In that time, it has hastened the end of Microsoft's Encarta encyclopedia and supplanted Britannica as the dominant reference work in English. While the digital landscape has changed drastically over the past decade, Wikipedia has not, and still delivers that rare site that strives for neutrality and accuracy, all with no commercial advertisements. READ MORE: Why people everywhere seem to love Wikipedia, according to Jimmy Wales It's hard to overstate how influential Wikipedia has been, not just as a free alternative to traditional knowledge sources, but as a vanguard for maintaining and delivering up-to-date information. Each month, nearly 100,000 volunteers around the world actively contribute content to Wikipedia so that anyone may freely read, copy or redistribute its articles. Dr James Heilman, a Canadian emergency room doctor and a volunteer Wikipedia editor, found that it was the most turned-to source of information on the internet during the height of the recent Ebola outbreak in West Africa. In the Journal of Medical Internet Research , he noted, "Wikipedia appears to be the single most used website for health information globally, exceeding traffic observed at the National Institutes of Health, WebMD and the World Health Organisation." With substantial editions in more than 100 languages, it has become a critical educational resource in emerging markets ignored by traditional publishers. However, Wikipedia, now an online digital "teenager", faces big questions about its identity and future direction. While its volunteer community emerged alongside blogs and MySpace - two "open web" platforms that have dramatically declined in the past decade - the encyclopedia continues to be relevant, timely and useful, even if its text-heavy front page looks old-fashioned compared with today's social media start-ups. Since its creation in 2001, Wikipedia has expanded beyond a simple encyclopedia to establish a greater "Wikimedia movement" that few people see but benefit from in profound, novel ways. The extension of the crowdsourced knowledge effort to "media" has spawned a range of projects, from the multimedia repository Wikimedia Commons to collaborations with world-class museums to the creation of Wikidata, the world's largest shared open-access database. "Wikipedia appears to be the single most used website for health information globally" Dr James Heilman Launched in 2012, Wikidata was designed to help Wikipedia structure 15 years' worth of users' text contributions into a database that allows for cross-referencing and linking to the outside world. By having precise technical descriptions of information in its database, Wikidata makes searching, filtering and joining collections of human knowledge possible on a massive scale. It has been so successful that Google cancelled its own similar project, Freebase, to throw its support behind Wikidata. In its announcement, the search giant noted the superiority of the Wikimedia project as a "community-driven effort to collect and curate structured knowledge". With Wikidata acting as a central database hub on the internet, the possibilities for cultural and educational institutions are staggering. A project called "Mix'N'Match" is already underway to use Wikidata as a hub that links museum collections. Prominent cultural institutions such as the Smithsonian, British Museum and the Getty Research Institute are joining their individual databases to Wikidata, thereby creating the ultimate directory - what some have called, after J.R.R. Tolkien, author of The Lord of the Rings , "one database to bind them". The evolution of Wikipedia beyond text-oriented articles can also be seen in efforts to add rich media, such as video and interactive content. Given the rise of video content on YouTube, Facebook and Vine, it is striking that video in Wikipedia is so sparse and low-quality, with only a fraction of a per cent of its articles hosting moving images. The potential for watching dance, sport or artistic technique in video or having interactive gadgets to explore physics and civil engineering models is still untapped. That's talking about just two dimensions. When it comes to the world of virtual reality and 3D objects, Wikipedia is even further behind. Overseeing the Wikimedia movement's financial and legal issues is the non-profit Wikimedia Foundation, based in San Francisco, which employs some 250 employees in a variety of fundraising, outreach and engineering positions. One of the roles the foundation has taken up is to advocate for the readers and users of Wikipedia by better understanding who uses the site and how the project can stay relevant to the public. The foundation even hosts monthly public metrics briefings by video-conference to evaluate trends and critical issues. Long-term problems, such as how to address Wikipedia's lack of women editors or how to reach more users in emerging economies, are frequently discussed. But recently, the foundation has even more reasons to be concerned. Visitors to Wikipedia, as measured by page views and unique users, have traditionally placed the site among the most visited in the world. After more than a decade of year-on-year growth, those numbers have been flat for the past year, even as the number of internet users is expanding globally. The lack of growth is a mystery, though this doesn't necessarily mean Wikipedia's influence has waned. Google, for example, uses Wikipedia extensively in its search engine and Knowledge Graph project, displaying information gleaned from Wiki pages directly in search results without requiring a user to visit Wikipedia. While this legitimate use of Wikipedia's content fulfills its mission of delivering the sum of all human knowledge to the public, it also deprives it of a chance to engage potential editors or donors. Perhaps the biggest challenge exists in the rapidly evolving computing landscape, with the dramatic shift towards mobiles as the dominant information device. A project by the Wikimedia Foundation called Wikipedia Zero has been successful in recognising this, by convincing mobile network operators to waive data charges for users accessing Wikipedia from their handsets. For developing countries, this initiative has the potential to bring a tremendous learning resource to millions over the air for nothing more than the price of the device. Unfortunately for Wikipedia, this global trend towards mobile could have a dramatic effect on the site's volunteer contributions. Are people going to help edit text articles on mobile devices with tiny on-screen keyboards or can the Wikimedia movement tap the potential of micro-contributions or use these multimedia-capable handsets for audio, video and photos from the crowd? Some of the answers depend on technological innovation and some on content innovation. Right now, the tension over the right approach is growing between the community of editors and the Wikimedia Foundation's board of directors. The relationship of the board and the community has reached one of the most acrimonious points in Wikipedia's history. A series of disputes has erupted over the past two years over who has the power to determine what technologies are deployed on Wikipedia, ranging from how images are displayed on articles to how to make Wikipedia easier to edit for newcomers. In a widely read blog post, Wikipedia veteran Liam Wyatt captured the frustration of many volunteer editors critical of the foundation's engineering efforts, saying the board treats the non-profit "as a technology organisation in the style of a dot-com company, out of step with the staff and without the awareness of the community". Last month, volunteer editors were surprised when one of the three community-elected members on the 10-person board (the previously mentioned Heilman) was removed by a majority vote of the board members with minimal explanation. Adding to the tension, one week later the board appointed two Silicon Valley veterans, Kelly Battles and Arnnon Geshuri, to replace two outgoing board members whose terms were ending. The optics of appointing two relative outsiders while ousting a well-regarded community figure was jarring. Not long after the board changes were announced, Wikipedia's editing community found that Geshuri was associated with the high-profile "do not poach" hiring controversy in 2010, when he was an executive at Google. The United States Department of Justice later pursued an antitrust class-action lawsuit that claimed Apple, Google, Intel and other technology firms mutually agreed not to recruit employees away from each other. His role in the case has alarmed many Wikipedia editors to the point that two former Wikimedia Foundation board members, both of whom served as chairs, have joined community outcry opposing Geshuri's appointment. To be fair, much of this tension goes unnoticed by the vast majority of Wikipedia's volunteer editors, who are more interested in the actual task of writing encyclopaedia articles. But the history of online communities has shown that long-term survival is difficult, and that confidence, once shaken, is hard to get back. In 1945, scientist Vannevar Bush described a hypothetical "memex" device that would serve as a memory and index to all of the world's information and communication. Wikipedia fulfils much of that original vision as a text reference for the world's major languages, but there is much more work to do. Forward-looking projects in the Wikimedia movement, based in fields such as interactive multimedia, 3D content and collaborative video editing, will take technological know-how and new types of contributor. At the same time, however, technology is not enough to keep the Wikimedia movement moving forward. Ultimately, Wikipedia was started by and still relies on the efforts of human volunteers. It will only thrive for another 15 years if that community can work cooperatively with the Wikimedia Foundation - and infighting doesn't splinter the movement. Andrew Lih is an associate professor of journalism at American University and the author of the book The Wikipedia Revolution: How a Bunch of Nobodies Created the World's Greatest Encyclopedia.