Halo: Reach is the second free game of the month for Xbox Live subscribers, and it's available now to download.
Now and through the end of the month, you can download the game for free through here. Reach is the second free Games with Gold game available this month, following Monaco: What's Yours is Mine, which is no longer available.
Crimson Dragon and Super Time Force remain the two free games for Xbox One.
So go ahead and nab it if you want to see how much Bungie has evolved between this and Destiny.