I say this because at first I was also excited just by watching that guy get excited, and then suddenly I was like "wait..isn't this already possible with pretty much 100s of libraries out there?"
Maybe someone can explain what makes this unique (so much so that the guy is so excited about it)?
From the processing website: > For the past fourteen years, Processing has promoted software literacy, particularly within the visual arts, and visual literacy within technology. Initially created to serve as a software sketchbook and to teach programming fundamentals within a visual context, Processing has also evolved into a development tool for professionals.
https://processing.org/overview/
They (Shiffman, in the video) have a pretty cool youtube channel where they use processing, p5, etc to teach programming, visualization, graphics, that kind of thing. I think it used to be called "coding rainbow" but he ran into copyright trouble I'm assuming.
openframeworks.cc is a vastly superior library IMHO (C++ though) for serious visual work.
Processing already has a JS port which can be used both with Javascript and a Java like language ( http://processingjs.org/ )
The book http://natureofcode.com which is a good starting point for creative coding uses ProcessingJS
With p5 you can get as close to the metal as you can in JS (for example, it has a WebGL based renderer if you want, and you can use typed arrays for your data). So it's a lot better.
Regarding OF: yes, for computationally intense stuff it's a lot faster, a native OpenGL application written in C++ should be faster than using JS in the browser.
However, it's also a lot more painful to develop in IMO. I tend to work out my sketches in p5js these days, then when I need performance port it over to OF. Given that most of the time the performance bottleneck is either "how many particles" or "how high-res is the input video", testing in p5 is a simple matter of scaling down.
If you read the various blog posts and interviews - the history of Processing at his department (NYU Tisch ITP) had a purpose of encouraging 'creative' people to explore and gain an exposure to programming.
All link to above can be found on his personal site - http://shiffman.net/
Processing was well thought out from a learnability standpoint, and p5 takes that and allows you to build some _very_ compelling lessons, modules and even whole CS courses that can be delivered and completed online. Because it's also JS, it means that if you can always augment an exercise with any of the rest of the JS ecosystem (for better or worse).