While U.S. Secretary of Education Arne Duncan marveled in 2014 that his kids could learn to code online using Khan Academy, a 1975 paper on Interactive Systems for Education notes that 650 students were learning programming online using PLATO during the Spring '75 semester http://files.eric.ed.gov/fulltext/ED102940.pdf

Khan Academy (2013) v. PLATO (1973) https://farm8.staticflickr.com/7307/11141723746_d2b239bd18_o...