In the spring of 2012, Anant Agarwal, a professor of computer science at MIT, taught a course called “Circuits and Electronics.” As usual, it was MIT-level challenging, requiring knowledge of differential equations and calculus. Unlike in the past, though, the course enrolled 155,000 students from 162 countries around the world.
 
It was the inaugural offering of what is now edX , an online learning venture of MIT and Harvard, which Agarwal helms. Through this nonprofit -- one of the leading forces of the massive open online course (MOOC) movement -- Agarwal aims to make higher education globally available, for free.
 
Which does not preclude in-person education. On campus, Agarwal is pushing for what he calls blended courses, which interweave digital content and face-to-face interactions. "I see online learning as a rising tide that will lift all boats,” Agarwal says.

Agarwal holds the Guinness World Record for the largest microphone array, and was named one of Forbes' top education innovators in 2012. Find him on Twitter at @agarwaledu.