Seems like instructure canvas is FOSS: https://github.com/instructure/canvas-lms/tree/master

If your line is GPL rather than AGPL there's Moodle.

But you do then have to have a sysadmin capable of managing an enterprise grade LAMP stack.

Canvas already is AGPL, though?

So it can be used by multiple universities who share the maintenance. That is my point: Not everybody has to develop their own.