September 15th was the 30th anniversary of the anniversary of X11
The X11 window system turns 30 years old today! X11 which still lives on through today via the X.Org Server on Linux, BSD, Solaris, and other operating systems is now three decades old.
https://www.phoronix.com/scan.php?page=news_item&px=X11-Turns-30 [phoronix.com]