The Awesomest Children Book Ever is 90
The Suprematic Tale about two Squares is definitely the awesomest, most progressive, innovative, creative, avant-garde, imaginative children (and adult) book.
It’s literally about two squares: the black and the red. It was written by El Lissitzky in 1922, the age of De Stijl, cubism and costructivism, and unfortunately it’s really hard to come by this days. The only copies I know about are 1980s reprints, and even those are very rare.
Take a look at the scans of all the pages and read about the tale.

