Less than 15% of Wikipedia's contributors are women

"In 10 short years, Wikipedia has accomplished some remarkable goals. More than 3.5 million articles in English? Done. More than 250 languages? Sure.
Why are there so many more men than women contributing to a "free encyclopedia that anyone can edit"?
But another number has proved to be an intractable obstacle for the online encyclopedia: surveys suggest that less than 15 percent of its hundreds of thousands of contributors are women.
About a year ago, the Wikimedia Foundation, the organization that runs Wikipedia, collaborated on a study of Wikipedia’s contributor base and discovered that it was barely 13 percent women; the average age of a contributor was in the mid-20s, according to the study by a joint center of the United Nations University and Maastricht University.
Sue Gardner, the executive director of the foundation, has set a goal to raise the share of female contributors to 25 percent by 2015, but she is running up against the traditions of the computer world and an obsessive fact-loving realm that is dominated by men and, some say, uncomfortable for women."
Source:  New York Times, 30th January 2011