MediaWiki - MediaWiki is a free software wiki package written in PHP, originally for use on Wikipedia.
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.
TiddlyWiki - a non-linear personal web notebook
Coursera - Build skills with courses, certificates, and degrees online from world-class universities and companies
Confluence - Confluence is content collaboration software that changes how modern teams work
edX - Best Courses. Top Institutions. Learn anytime, anywhere.