DerekCZ is an author of "YWot Ultimate Sandbox" map, which used to be interactive world with a lot of functions and additional actions, such as commands, warps, and even minigames. The map used to be located at URL /~DerekCZ/[1] , but all scripts were stopped in 2014, and map was made private in 2015.

It is now again possible to go to the world (ywot/~DerekCZ/[2]), but no more scripts are active anymore and the original map was removed. There are only two "areas", "Member zone" located at the left side of "welcome" screen and a tombstone saying "RIP Ultimate Sandbox" located at the right-down side of the "welcome" area.

Sad story bruh...