hn.academy - Collects, ranks, and showcases the online courses recommended by Hacker News users.
Class Central - Search online courses.
Pluralsight - Courses platform.
Open edX - Code that powers edX. Includes the LMS (student-facing, delivering courseware), and Studio (course authoring) components.
Avocado Audio - Platform for the world’s best audio courses.
Coursera - Build Skills with Online Courses from Top Institutions.