“Education technology has become a busy space in recent years. Mark Zuckerberg and Bill Gates continue to push the envelope with enormous philanthropic gifts toward education reform; Blackboard.com was traded at a $1 billion plus valuation; and Google is putting millions into education tech sites like KhanAcademy. At Mashable, you’ve read about social campaigns for education, gaming in education and free educational resources. With so many startups on the scene, it is easy to get lost. Fortunately, most innovation is centered around a short list of fundamental ideas. In this post, we’ll walk through nine clusters of education tech companies.” - × × ×