As you may or may not know, this feed runs on are.na ... another thing you may or may not know is that I have a self imposed constraint to have no javascript on this feed. So how do I add categories?
So they're going to be implemented as channels. I will connect blocks from the main channel into these category channels. So blocks can appear in multiple categories. And for the rendering of this there's two options.
The easiest way would be to just create pages for categories/tags/projects. So each channel would just turn into a file, and then on the main feed I can visit these pages.
The other... actually I'm just going to stick to the easiest way. I have too much other stuff to do :)