gnome-font-viewer hangs entire OS
I shudder to think how untested this thing is...
Go to:
https://www.google.com/get/noto
Click the big red "DOWNLOAD ALL FONTS" button. Unzip them into a folder. In a terminal, CD into the folder containing all the font (TTF) files. Then run gnome-font-viewer. Entire OS hangs apart from mouse movement -- or if you're lucky, you get a crash dump with some warnings about a likely bug. Looks like a buffer overflow, if I had to guess.