Wikipedia turns 25 and reflects on a quarter century of open knowledge

Today marks the 25th anniversary of Wikipedia, the free online encyclopedia that has become one of the most visited reference sites in the world since its launch on January 15, 2001 by founders Jimmy Wales and Larry Sanger. What began as a modest experiment has grown into a global repository of knowledge, in use by billions of people worldwide.

Wikipedia was first launched as a complement to the expert‑review model of Nupedia before quickly becoming a collaborative platform where volunteers from around the world could write and edit articles. Over the past quarter century, it has expanded far beyond its humble beginnings, now hosting more than 65 million articles in over 300 languages and drawing roughly 15 billion views each month.

To mark the milestone, the Wikimedia Foundation, the nonprofit organisation that operates Wikipedia, has rolled out a series of celebratory initiatives under its Wikipedia 25 campaign, including a documentary‑style look at volunteer editors and virtual events geared toward engaging the global community that keeps the site running.

Throughout its history, Wikipedia has depended on volunteers to write, edit and fact‑check its articles. The site’s model of open editing has ushered in both praise for its accessibility and scrutiny for occasional inaccuracies, yet its impact on global information access is undeniable.