Electronic Arts' little worker bees have packaged up the toolset they used to create the levels in Command & Conquer 3: Tiberium Wars and they've decided to let you have it.
Seems like a mistake to us, but never mind. You can grab it from the official website, where it will take up 7.7MB of your time.
One of the reasons it wasn't shipped with the game in the box can be found in the form of the 100-plus-page instruction manual, which ought to help those of you starting from scratch as well as advanced and returning users.
It took a lot of time to assemble, what with the various changes made during development of C&C3 that needed to be documented, says EA. They also had to cut out references to previous projects and old functionality.
Fortunately it's all done now, and ready for you to use in the creation of multiplayer and skirmish maps.