Not completely. Proprietary modules and forks of both exist, so in the broadest sense they are not (in the sense of, if I'm ever handed a copy of something call

Not completely. Proprietary modules and forks of both exist, so in the broadest sense they are not (in the sense of, if I'm ever handed a copy of something calling itself LLVM, I do not know that it is libre software). By your definition, any non-copyleft open source licensed software ceases to be open source 'in the broadest sense' once a proprietary fork exists. Which is just silly, some software is open source according to the open source definition or it is not. Imagine that Apple wants to do something nifty for Swift, but doesn't want Google to be able to use it in Go -- they'll release a proprietary module that can be linked into Clang. People who pick the Apache, MIT, or any non-copyleft open source license do this knowing that proprietary forks or extensions are possible. Not everyone's definition of 'freedom' is the same as the FSF. Also, I would like to point out that the same thing happens in copyleft-land. Companies dual-license their code under a proprietary license and let contributors sign agreements, to shut out competitors and to get people to buy expensive proprietary licenses. Oracle thankfully uses the GPL for such strategies. In fact, they recently relicensed Berkeley DB and Berkeley DB XML under the AGPL(!). I'm sure that the libre software world being based on a proprietary compile will be a great thing to add into the mix of pervasive surveillance and network penetration. Just help me understand. FreeBSD takes the open source LLVM/clang, uses it to compile their open source software. And suddenly it becomes proprietary. How so?