Moodle

Modular-Object-Oriented-Dynamic-Learning-Environment, known as Moodle is an online course management system

The system is can be used by anyone and it’s all free. It‘s accessible in 150 country 70 language. Both students and teachers can access the site easily in this link https://moodle.org/?lang=tr

Unlimited number of students can participate in courses and classes. Homeworks, notes, feedbacks and announcements can be added in this site.