Why do designers use the « X » sign to close a computer window?

X to Close — Solve for X — Medium

The history of UI/UX is always a fascinating read. Even as I speak japanese, I had never thought that « x » and « o » were batsu (cancel) and maru (validate) – and that the « x » metaphor was also shown on Playstation controllers.

The search for the origins of the « x » go back to Atari TOS, but I think the author should have been looking for text-based graphical interfaces that were being used in DOS and other non-graphical OS at the time.

Awesome little piece anyway.

Update: apparently, the « X » sign in Windows was not used to close the window, but to open a menu…

Re-update: There is more to the batsu/maru story. In Japan, O is yes, and X is no. But it was reverted in occident to take into account the idea that western people cross checkboxes when they validate something. 

Via: X to Close — Solve for X — Medium.