Dev is like a mod it can make you jump really high to making you invincible. To get dev you have to go to www.halomaps.org and go to utilities when you find dev you click download you can save it any where I recommend saving it on your desktop for easy access. If you get the newer version of dev you have to type all the codes your self. When you play halo ce you have to leave dev off until you join a game or make a game. A simpler way to turn dev on and off you can push page up to turn it on and page down to turn it off  when you make a game the button to bring up the screen for dev is ~ after you push it a screen will come up at the bottom of the screen you type the code in there if the code is rite it will say “true” at the top of the bar. Here are some codes.

Cheat_all_powerups              will make one of all the powerups

                        spawn around you.

                                                    Cheat_all_vehicles                  this spawns one of each vehicle around you

                                                    cheat_all_weapons                     makes all weapons around you   

                                                    cheat_spawn_warthog                spawns one warthog by you

                                                   cheat_bump_possession 1              allows you to take over ai’s bodys        

                                                   cheat_deathless_player 1               makes you invincible and every

                                                                                                        body else to

                                                    cheat_medusa 1                              who ever looks at you dies

                                                    cheat_super_jump 1                        jump really high Note:will die

                                                                                                            when falling so might want to

                                                                                                           put invincibility on

                                                     cheat_bottomless_clip 1                 infinite ammo