4. Sue Gardner, Wikimedia Foundation

In her role as executive director of the Wikimedia Foundation, Sue Gardner oversees none other than , the global resource with more than 14 million volunteer-authored articles in over 250 languages. Since joining the foundation in 2007, Gardner has more than tripled revenues, helped increase global readership by 85 percent and instituted a variety of new projects and activities. Like Mozilla's Baker, Gardner also recently joined the Ada Initiative as an advisor.

"I believe we need to understand the origins of our gender gap before we can solve it," Gardner wrote in a recently, discussing the paucity of women editors on Wikipedia. "And the people talking ... are exactly the ones we should be listening to, because they're all basically one degree of separation from us already, just by virtue of caring enough to talk about the problem."

5. Sheryl Sandberg, Facebook

Sheryl Sandberg is now Facebook's chief operating officer, but previously she's held positions and Google and the World Bank. With an academic background that includes a Harvard MBA, Sandberg has also been an outspoken advocate of women in leadership, including speaking on the topic at a recent TED conference.