With a catalog of over 2000 videos on subjects from statistics, to history, to organic chemistry, Khan Academy has become the world's most popular educational website.

Founder Salman Khan has made all the movies himself, and if you've never watched one, go to his site now. Pick a subject. Watch and learn. But pay particular attention to how the video is made, how the teaching happens, how the story is told. These are not videos of a teacher standing in front of a blackboard (whiteboard, whatever), lecturing at students and making a few gestures for emphasis and scribbles as examples. Khan's videos are screen-captures, focusing solely on the notes he makes as he talks through a topic. And as a result, the videos are meant to feel more intimate and more compelling.

Although Khan Academy is now a team of six, the project very much centers around Salman Khan. It's his vision.

I had the opportunity to speak with him last night before he took the stage as part of a panel for MIT/Stanford VLAB's event "Declassifying Education."

I asked how Khan how you scale something like Khan Academy -- one guy, one camera, and a world of knowledge to teach. He said that there were two factors in scaling. One was simply the distribution, and to a large degree, he said, the technology takes care of that. Khan Academy boasts over 30,000,000 lessons delivered, and as the Internet infrastructure expands globally, the school's reach will expand with it.

The other part of scaling is, of course, content. And again, technology helps -- record a video once, and you have that lesson on, say, differential equations forever. Khan simply makes more videos, focusing particularly on STEM subjects as those aren't taught well -- or at all -- in schools. However, "teachers don't scale," said Khan. You can't simply replicate teachers the way you can print textbooks, so the trick, according to Khan is to make sure those "good ones" can have their instruction broadcast as widely as possible.

Scaling Khan Academy also involves building out other elements of the virtual school. In addition to the videos for which Khan Academy first became famous, the site now offers a supplemental exercise platform as well as analytics to help track students' progress - all of which remains free and open. Khan Academy plans to add a component soon that will allow students to do some of the tutoring themselves.

"Why now?" I asked him. Why, after making videos since 2004, has he suddenly skyrocketed to fame -- dubbed the "savior of education," not to mention "Bill Gates's favorite teacher"? "It's a good story," he admitted, pointing to a series of articles and reports that helped to build the site's reputation. But he said that the site was already seeing steady growth when the media picked up on the story. Students (and their parents) are hungry for this sort of online educational resource.

It isn't just journalists and students that have been drawn to the site; it's caught the attention of investors too. But Khan Academy has maintained its status as a non-profit, supported in part by the Gates Foundation and Google 10^100. That not-for-profit element is fundamental to Khan's vision.

That vision really seems to be about lowering the barriers of access to education, about opening content, and about teaching the world. Khan spoke of a future in which it doesn't matter which school you graduated from -- whether in Palo Alto or Calcutta -- as long as you can point to analytics about your performance online, and make the argument that you are actually an engineering students with one-in-a-thousand sorts of skills. In doing this, Khan Academy seeks to foster a "global meritocracy."