Plantoost - Plantoost is an online learning and teaching platform where educational content creators share their knowledge and make a living doing what they love.
EarMaster - Professional software for ear training and practical music theory on Windows and Mac.
SabiTeach - A guaranteed way to find a tutor
GNU Solfege - GNU Solfege is free music education software.
Coursera - Build skills with courses, certificates, and degrees online from world-class universities and companies
Meludia - Listening exercises and to sharpen your ear and music theory skills