Edx was started by Harvad University and MITs MOOC’s and now more than 50 universities are enrolled with it.
You will get almost all course in all field totally free and also a certificate if you complete that programme effectively.
Now it has become the largest online portel for learning and you can get courses from renowned universities around the world and India too like IIT mumbai, etc.
You will get videos, lectures and theory for the subject that you have taken.
I have registered for many courses that are related to my field and you can too register.
There are many topics which will interest you. So if you want to learn something new and exiting from the universities around the world then surely go for it.