Teachable - Create and sell beautiful online courses with the platform used by the best online entrepreneurs to sell $100m+ to over 4 million students worldwide.

Khan Academy - Khan Academy offers online tools to help students learn about a variety of important school subjects. Tools include videos, practice exercises, and materials for instructors. Read more about Khan Academy.

Clever - syncing between education applications for K-12 schools

InfoCoBuild - It's a place where you can enjoy some time watching documentary films, open lectures from educational institutions or reading the latest news.

Claroline - Claroline is a collaborative eLearning and eWorking platform.

Brilliant.org - Brilliant - Understand concepts and build your problem solving skills with thousands of free problems and examples in math, science, and engineering.