Reddit's 2017 April Fool's joke is located at /r/place. It allows users who have been around before March 31, 2017 to place a colored pixel on a canvas every 5 minutes. Initially, it was chaos, but amazingly, some subreddits have banded together to actually create real pixel art. This is all done over the internet and if you look at the screengrab here, some of these art pieces are quite large.
It kind of reminds me of The Million Dollar Homepage.