A: Stanford, California, United States
Sebastian Thrun, Research Professor Computer Science at Stanford and a leading roboticist, and Peter Norvig, Director of Research at Google, Inc., in partnership with the Stanford University School of Engineering, offered a free online course entitled An Introduction to Artificial Intelligence.
According to an article by John Markoff in The New York Times, by August 15, 2011 more than 58,000 students from around the world registered for this free course— nearly four times Stanford's entire student body.
"The online students will not get Stanford grades or credit, but they will be ranked in comparison to the work of other online students and will receive a 'statement of accomplishment.'
"For the artificial intelligence course, students may need some higher math, like linear algebra and probability theory, but there are no restrictions to online participation. So far, the age range is from high school to retirees, and the course has attracted interest from more than 175 countries" (http://www.nytimes.com/2011/08/16/science/16stanford.html?hpw, accessed 08-16-2011).
One fairly obvious reason why so many studients signed up is that Norvig is famous in the field as the co-author with Stuart Russell of the standard textbook on AI, Artificial Intelligence: A Modern Approach (first edition: 1995), which has been translated into many languages and has sold over 200,000 copies.