edX

edX started as a nonprofit joint venture between Harvard and MIT before being acquired by 2U in 2021, and its catalog still leans on that university pedigree, with course material from institutions like Berkeley, Columbia, and the University of Michigan. The core model mirrors Coursera's: audit almost anything for free, pay for a Verified Certificate with identity checks, and stack certificates into a MicroMasters credential that some partner universities accept as credit toward an actual degree.

The open-source software behind the platform, Open edX, also runs independently at other institutions, so an edX-style course shows up beyond edx.org itself under different university branding. For a learner, the appeal is depth and rigor over polish; courses can run longer and denser than a Udemy course on the same topic, aimed at someone treating this as real coursework rather than a weekend skill refresh.