Java Applets feel outdated and archaic, especially with the explosion of powerful javascript rendering libraries like three.js. However the upload process for getting processing.js files into WordPress is also extremely annoying. I like to work in the native .PDE format, referencing that like so
data-processing-sources="my_test.pde"
But WordPress won’t let me upload files with a .pde extension. I can change the extension to .js and then upload it, but even then I still have to reference it by the absolute path. And don’t even get me started on how to include additional data like .jpg’s.
The ProcessingJS word press plugin provides a wrapper to write processing code directly inside of the WordPress blog editing field. But who wants to write code there? You can copy/paste from another editor but all the data paths will still need to be touched up.
My favorite part of processing is the feeling of creativity and spontaneity it fosters. Processing.js is powerful, but for me the overhead it requires is still just a bit too much. For example I just spent the afternooon wrestling with HTML instead of actually making something fun! So for now… i think I’ll just stick with the standard Processing environment, and if I make something I like take a video 
Plus that way I can go nuts with ridiculously expensive GPU rendering!