> Corporations can't embrace-extend-extinguish open source. This is because the source is always available. Sure they can use that knowledge to build a new, more popular, thing, but the existing source never goes away. It represents an un-enclosable commons.

Some counter-examples:

* git is now mostly github

* khtml is now mostly chrome

* linux is now more android and chromeos than linux. Anyhow, the plain kernel is deeply corporate.

You can still fork those project. But it would be mostly meaningless to do so.