Microsoft has released Halo 3: ODST for Xbox One today, a day after the initial release was leaked to be.
Those who purchased Halo: The Master Chief Collection before the 19th December 2014 should see a code being sent to your Xbox messages available on your console, SmartGlass or Xbox.com to get the game for free.
If you did not purchase Halo: The Master Chief Collection you can also purchase Halo 3: ODST from the Xbox One Markstplace for $4.99/£3.99.
The 8.1GB download requires Halo: The Master Chief Collection to play and is not a stand alone title.
As well as ODST being made available, a new update has been released for The Master Chief Collection which targets improvements to matchmaking, adds another remade Halo 2 multiplayer map to the mix, Remnant, as well as two additional game modes: Team Doubles and Big Team Battle.