Bungie released editors with its previous games in the Myth and Marathon series.

It has been rumored that the underpinnings of the Halo engine are highly customizable; however, the Xbox itself will not have any capacity to run such an editor, and it is not believed that there will be any mechanism for altering the game on that platform.

It is not yet known how editable the release of Halo for the Windows and Macintosh will be, or whether it will ship with an editor and if so for what platform.