"C" is one of the most widely used programming languages of all time. Prof Brian Kernighan wrote the book on "C", well, co-wrote it - on a visit to the University of Nottingham we asked him how it came about. "Most Difficult Program" - Ackermann Function: http://youtu.be/i7sm9dzFtEI Computer That Changed Everything - Altair 8800: https://youtu.be/6LYRgrqJgDc Factory of Ideas - Working at Bell Labs: https://youtu.be/QFK6RG47bww More from BWK on other computer languages at: https://www.youtube.com/watch?v=Sg4U4r_AgJU http://www.facebook.com/computerphile https://twitter.com/computer_phile This video was filmed and edited by Sean Riley. Computer Science at the University of Nottingham: http://bit.ly/nottscomputer Computerphile is a sister project to Brady Haran's Numberphile. More at http://www.bradyharan.com