<< "Microsoft and Apple aren’t going to open up all their stuff. But they all create programs that put pixels on the screen. And if we can modify those pixels, then we can change the program’s apparent behavior" >>.

...so, IMHO this "breakthrough" is nowhere near as cool as real, honest-to-goodness FLOSS. By saying << this "breakthrough" >>, I mean both a thing called "Prefab", which the article talks about, and the idea contained in the above quote, which (I think) is the idea behind Prefab. (Apparently, Prefab is a code implementation of that idea.) Prefab seems to be intended to give the user a sort of "pseudo" ability to modify a closed-source, proprietary, non-free app. -- [well, at least, to modify its user interface]. (In fact, what the article says, is "any" app; -- which to me sounds exaggerated.)

Among the advantages it does NOT have -- (but free / open-source software does) -- is the ability to study the source code, in order to gain an understanding of the design -- that is, how the whole app -- (not just the user interface) -- works. (how it is "supposed to" work; or, how it was intended to work). Sometimes that opportunity might even be a good substitute (in a pinch) for having well written user documentation. It might even provide someone who was not the author / designer of the code, a good basis for writing said documentation -- that is, a way to learn enough about it, to be able to write the user documentation; and *that* ["educational" aspect] may be outside the scope of Prefab, and of [1].

In fact, it occurs to me now (and probably to some others long ago!), that one of the DISadvantages of "vendor lock-in" -ware, is that hiding some of the "knowledge" that is in the source code, requires keeping the design so secret, that the quality of the "end user" documentation might have to be limited intentionally. If the "end user" documentation gets too good, then it might start to impart to the reader, some of that same "knowledge"; -- which (of course) is FINE in the case of FLOSS! But if you want it to be technically difficult -- [as well as, perhaps prohibited by the terms of some EULA] -- for anyone to reverse engineer your app, or even some part of it, like one feature that it offers, then you have to impose an "NDA" on yourself -- an NDA that would (of course) be N/A in the FLOSS world.

On the other hand, I still like this article [1] somewhat (and the idea of Prefab), because I think it does begin to entice the user (of "secret"-ware) (that is, non-free / non-OSS software) with some of the appealing aspects (and maybe convince that user of some of the benefits) of being able to modify a software app, "other than" by begging the vendor to change it, and then just hoping / praying. That is just one of the advantages of FLOSS. But it is a big one.