It's just a standard BSD 3-clause license, see: http://opensource.org/licenses/BSD-3-Clause

... which he says at the bottom of the page. I'll leave the monument to my ignorance above, in case it helps someone else.

Moreover, they don't really adhere to their own license: http://cdn.plyr.io/1.0.19/plyr.js doesn't reproduce the copyright notice despite being a redistribution in binary (or source???) form. If you just copy&paste that file into your own project you are in violation of their license.

On the upside, likely nobody cares. I doubt anybody has ever been sued over violating the BSD license.

I've always assumed "All rights reserved" was just a redundant part of the copyright declaration (it's already copyrighted, what else can you possibly reserve without e.g. trademark or patent law etc?), and that the explicit copyright license that usually follows and grants exceptions to the copyright is all that matters.

I hadn't thought about it much until now though, perhaps that assumption is wrong in some jurisdictions.

I'll admit, this is my first open source project and I didn't know what to do license wise. I've now changed it to the MIT license as that seemed the most appropriate? Basically we're not going to sue you if you modify or use it. Frankly I'm happy it's been so well received. Thanks for the feedback!