Being almost entirely self taught when it comes to quantitative finance, I believe that quant education (and all education in fact) should be open and accessible to everybody. During my studies I have found the following online educational resources very useful.
TED (Technology, Entertainment, Design) is a global set of conferences owned by the private non-profit Sapling Foundation, under the slogan "ideas worth spreading".
Khan Academy is a non-profit educational website created in 2006 by educator Salman Khan to provide "a free, world-class education for anyone, anywhere. Resources cover finance, physics, general chemistry, biology, astronomy, economics, macroeconomics, microeconomics, computer science, and more.
Udacity is a for-profit educational organization founded by Sebastian Thrun, David Stavens, and Mike Sokolsky offering massive open online courses taught by industry leaders from companies such as Google, Facebook, Cloudera, and MongoDB.
Coursera is a for-profit educational technology company offering massive open online courses (MOOCs) founded by computer science professors Andrew Ng and Daphne Koller from Stanford University. Coursera works with universities to make some of their courses available online, and offers courses in physics, engineering, humanities, medicine, biology, social sciences, mathematics, business, computer science, and other subjects. As of April 2014, Coursera has 7.1 million users in 641 courses.