Knell is the President and CEO of NPR. Previously he was the CEO Sesame Workshop, the nonprofit organization behind the beloved PBS classic Sesame Street, from 2000-2011.

A lawyer by training, Knell began his career in government. His career in the TV industry began when he took a job as counsel to WNET/Channel 13 in New York. In 1989, he became the VP of legal affairs at Sesame Workshop (then known as CTW, or Children's Television Workshop), the kid-oriented media enterprise founded by Joan Ganz Cooney. After seven years, having risen to executive vice president, he felt restless and resigned. He had a stint at the Asian media company Manager Media International, but was lured back to CTW in 1998 and named president and CEO position in January 2000. These days, as he explains, he's "the only CEO who has to show the Potty-Time Elmo to the Board of Directors, which can feel really pathetic." Despite his trepidation, he stuck with Sesame Workshop for over a decade but departed to the more serious NPR at the end of 2011.

Knell's main project with the Sesame Workshop involved working with local media outlets in foreign countries to produce regionally appropriate versions of Sesame Street. The show is now seen in 120 countries, including South Africa, Russia, China, and Egypt. What Knell likes to call "muppet diplomacy" has been tremendously successful, even in countries where anti-Americanism is widespread. [Image via Getty]