On what date was Wikipedia launched as a public website?

Wikipedia was launched as a public website on 15 January 2001.

Jimmy Wales and Larry Sanger created Wikipedia as a free, collaboratively edited encyclopedia. It began as a companion project to Nupedia, an earlier encyclopedia whose articles followed a more formal expert-review process. Wikipedia’s wiki software allowed readers to create and edit pages quickly.

The site initially used the domain wikipedia.com. Its open editing model enabled rapid growth, because volunteers could improve articles without waiting for a centralized publishing schedule. Wikimedia Foundation, a nonprofit organization, was established in 2003 to support Wikipedia and related projects.

Wikipedia is not the first online encyclopedia, and its articles are not automatically authoritative simply because they appear on the site. Pages can be edited by many contributors, and reliable research normally requires checking citations and independent sources.

Nevertheless, its multilingual, volunteer-built model made Wikipedia one of the most influential reference projects on the Internet.