On Sat, Nov 05, 2016 at 06:13:58PM +0100, Tobias Geerinckx-Rice wrote:
> I've had a package for the ‘zstd’ compressor lying about for quite some
> time — since before its weird appropriation by Facebook Inc. as a PR
> tool. Apart from that, it's nice. It's fast. Why not upstream it.
> 
> While updating and cleaning it up for submission, I noticed a ‘PATENTS’
> file[0] that sounds vaguely threatening, or at least tries to do. IANAL
> enough to tell.
> 
> Any opinions on its meaningfulness? Does it affect the (BSD-3) licence
> at all? Does zstd still belong in Guix?

My 2¢ are quoted from the GNU Free System Distribution Guidelines
[0], which Guix does follow:

------
Patents

It is effectively impossible for free software developers and
distributors to know whether or not a given piece of software infringes
any patents: there are too many of them, they vary from country to
country, they're often worded so as to make it hard to tell what they do
or don't cover, and it isn't easy to tell which ones are valid.
Therefore, we don't generally ask free system distributions to exclude
software because of possible threats from patents. On the other hand, we
also don't object if a distributor chooses to omit some software in
order to avoid patent risk.
------

But like I said, my opinion on this subject is only worth 2¢ ;)

Also see the statement by the maintainer / author Yann Collet:
https://github.com/facebook/zstd/issues/335#issuecomment-245011724

[0]
https://www.gnu.org/distros/free-system-distribution-guidelines.en.html