Halo: Custom Edition, sometimes abbreviated Halo CE, is a free stand-alone expansion for Halo Combat Evolved by Bungie Studios, which was ported to the PC by Gearbox Software. Halo CE was released by Gearbox as an unsupported add-on, which requires the original game. To prevent confusion between Halo Custom Edition and Halo: Combat Evolved (which can both be expressed as Halo CE) the original version of Halo (Combat Evolved) is referred to as Halo PC.
What does Halo: CE do?Edit
Now, if you don't have Halo: PC you would be wondering "What does Halo: CE do?" Well, Halo: CE lets anyone use user-created content (score!) How do you make user-created content? Use the Halo: CE Editing Kit (think of it like a level and object editor.) Sadly, their's a catch to Halo: CE. It's multiplayer-only, no single-player use. Regardless, if you have Halo: PC get this add-on. It makes Halo: PC 1000x better!
Downloads for Halo CEEdit