[Third+Final Prompt] Where do you organize your worldbuilding?

I used to write on basically any piece of paper that would come my way, up to and including stuff that I should really have kept clean. Stupid amounts of halfway filled notebooks, bills and receits, work memos and sometimes even important docs wrong face up on the desk... Never the proverbial napkin though (pen goes right through that crap). After ending up with huge folders that ate too much space and basically made it impossible to find my way through stuff I got an e-ink tablet. Now it's just as much of a mess but I can at least cary it around and I don't have to worry about some kind of work related stuff randomly having alien morphology specs on it. When I'm in good spirits, like most people here it seems, I will try to make sense out of it and put it on an organized Word file.