If y'all are interested in cube plugins:
http://prntscr.com/dma43p
As you can see they use: WorldEdit, ProtocolLib, GameManager, NoCheatPlus. <- These are all open plugins.
WorldEdit: https://dev.bukkit.org/projects/worldedit
ProtocolLib: https://www.spigotmc.org/resources/protocollib.1997/...