Really nice work compared to what I consider to be the quite bad Brotli -- an incredibly slow compression standard that only ended up in browsers because it was created by Google.
That being said: has anyone actually given any indication that there are any relevant patents in the first place?
Using zstd gives Facebook a free license on ALL your patents.
Using Opus gives Facebook only a license on patents that apply to Opus.
So no, large tech companies can and have given MUCH better grants for compression tech, than Facebook is doing.
I just read the Opus patent summary. It seems like if zstd followed the same license using it wouldn't give facebook any license but if I sue facebook I loose the licese to use zstd. Am I correct in that.
If you accept the job you give up your work. It's not like there's no compensation.
Am I correct in that.
Yes, the retaliation (and hence, implicit license to Facebook) is only for the technology itself.
Because as far as I can see, Facebook has an exception saying that if they for some reason patent-sue you first, you would be allowed to countersue without losing your license to their patents.
That could be a misinterpretation, I suppose. But if it's right, then Facebook's license seems superior for those parties who wish to end software patents.
It's mostly superior for Facebook. If you're a party that wants to end software patents, but intends to use zstd in any place you might want to interface with a company that doesn't hold the same position, then you're screwed.
If you want to end software patents, and Facebook sues with one (not applying to zstd), you're also still screwed. This is relevant because even if you're against software patents, you can take them out defensively. But this license makes that useless.
Compare to GPL vs LGPL, or how the free software codecs all eventually moved to BSD.