Wikipedia’s New Chief: From Soviet Union to World’s Sixth-Largest Site

She will succeed Sue Gardner, a former Canadian journalist, on June 1. Gardner will become a special adviser to the foundation, it said in a news release.

Tretikov will lead the nonprofit foundation, set strategy and manage operations for the global, volunteer-driven site, used by more than a half-billion people. In a statement, she described Wikimedia’s mission as “nothing less than making the sum of all human knowledge freely available to all.”

Website-ranking service Alexa ranks Wikipedia sixth in the world in traffic behind Google.com, Facebook.com, YouTube.com, Yahoo.com, and Baidu.com, the Chinese search engine.

Previous leadership has wrestled with challenges. In October, top editors banned 250 accounts because of dozens of suspicious articles that may have been manipulated by users with a conflict of interest.

Spokesman Jay Walsh said Tretikov would address that issue as a priority. “We are really pushing toward more transparency,” he said in a telephone interview. “We are reinforcing that paid advocacy is not welcome.”

Initiatives to involve greater diversity of contributors, better mobile support of Wikipedia, new geo-location tools to find local content more easily, and more tools for users in the second and third world are also priorities, Walsh said.

The foundation relies on contributions and grants for funding. Its net assets have grown from $57,000 in 2004 to $45.2M at the end of fiscal year ended June 30, 2013.