Steam users will be able to enjoy Rare's pirate game Sea of Thieves at some point.
Page on Steam Sea of Thieves Has appeared and pointed out that the game is "coming soon".
Microsoft says cross-platform gaming will allow Xbox One, Windows 10, and Steam users to play games together when launched on Steam.
Back in May last year, Microsoft said that its Xbox game studio PC games would appear on Steam, including Gears of War 5.
The company said at the time that its goal was to make Xbox Game Studios PC games available to more players.
Currently, more than 20 Microsoft products are available on the service, including part of Halo: The Master Chief Collection.