Courses: 22 courses in four categories. Pictured here: Sebastian Thrun's pen is one of your guides to Udacity's artificial intelligence class.
Focus: Increasing access to college-level courses.
Sources for courses: Udacity, corporate partners such as Google, university partners such as San Jose State.
Backed by: $21 million in venture capital from Andreessen Horowitz, Charles River Ventures and others.
Status: For profit.
Leadership: CEO and co-founder Sebastian Thrun.