for any one studying ancient or otherwise dead languages, this is a must:
fsi-languages.yojik.eu/ audio courses for learning languages developed by the us government foreign service institute now in the public domain. in additon to more popular languages, here you can find courses in languages such as lao, igbo, hebrew, romanian.
great comprehensive list of different resources for game developers
also some of the best ableton live tutorials here!
project gutenberg. tens of thousands of public domain books available to download
what is the best source to register for celta certificate online?
www.codecademy.com/ for people starting out in coding
also for good and thought provoking content on science and philosophy check out www.youtube.com/user/vsauce