This is a small mod that enables the game's built-in cheat tools. This can be useful for mod developers or if you just want to play the game in creative mode. The menus are shown by default, but can be toggled by a new entry in the game's main menu. A toolbar will appear at the top of the screen and an additional Cheats section will show up in most info panels on the right side of the screen. Many of the cheat commands have keyboard shortcuts and these will function even when the menu is hidden.
Mod devs: Take a look at the source code to see how you can easily add additional menu items or entire menus to the toolbar!