Not really. They are based on open standards that use functionality that happens to be faster under V8 (chrome's javascript engine).
In fact, this uses threejs[1] under the hood. It is just that the version of Firefox someone is using sucks in comparison to Chrome for the three.js stuff (likely WebGL).
In practice, an "open standard" that has only been suitably implemented by just one party really isn't all that open.
Now, maybe there's a greater chance that the situation will change, and other suitable implementations will eventually arise. But until that happens, an open standard with one usable implementation really isn't different from a closed standard at all.
I would counter that and say, "An 'Open Standard' created and then implemented by 1 party is no different than a closed standard".
However, Khronos[1], the entity that makes opengl, also made the webgl standard. The fact that mozilla hasn't done as good of a job implementing it as google has doesn't magically negate the fact that it is still an open standard (that mozilla has actually implemented, just poorly).
Specifically for these experiments though, CSS 3D transform has been implemented based on the same working draft for quite a while, and it's mostly being edited by folks from Apple. Firefox being slow really has little to do with people optimizing for Chrome.
This behavior people have been railing against for years is once again standard.