story
Exactly (for now). It has a clear problem statement (the functionality is great but the API is awful) and then demonstrates how it solves the problem.
> C4 sets itself apart because it handles interactivity (gestures, etc.) and audio / video. > You can draw / animate, and build fully interactive interfaces.
That cannot be what sets C4 apart, because the APIs that C4 is built on top of let you do all of these things.
It's as if I wrote that what sets MPWDrawingContext apart is that it lets you draw beautiful graphics. While it is true that you can draw beautiful graphics with MPWDrawingContext, you can draw those same beautiful graphics with CGContext, so that is not the distinguishing feature. The distinguishing feature is that doing so is just much more painful with CGContext and much more pleasant with MPWDrawingContext.
Framing it this way makes it immediately clear whether you might want to look at MPWDrawingContext (you don't find the CG API very pleasant to use) and helps you evaluate it (looks more pleasant to me, I'll give it a try vs. that looks worse than CG, close the window).
For C4, the first guess is that it's like Processing, but then I see that there's no interactive app, which to me is the key distinguishing feature of Processing. Since you don't currently have an interactive app, my guess would be that you are saying you have libraries that are "Processing-like", is that correct?
I personally always thought those particular libraries were fairly nondescript/generic graphics libraries, so possibly that's what I don't understand and maybe what you might need to explain.
The two examples you have on the home page don't make a very compelling case for the fairly grand claims, width vs. size.width is at best questionable, and CA/UIKit have both implicit and block-based animations that look just as good as the example you give.