Literally translates to "Not crack up".
Said when something is not funny.
The opposite of crack up.
Created by finding the opposite of crack(ed) which is obviously abandonware & the opposite of up which has to be down.
I'm all out of weed and there is no where to get anymore = ABANDONWARE DOWN!
Bob: "hey dude stop dumping stuff all over the place"
John: "I dump that stuff right there for you"
Bob: "Abandonware Down!!!"
Bob: "Did you see that homey on the computer poking the
screen with his back-seat browser brothers bothering everyone?"