Friendly Fire refers to a set of features intended for the Games Explorer when Windows Vista was codenamed Longhorn. Friendly Fire aimed to enable users to play games and collaborate with their Windows Messenger contacts and was presented as an option from within the Games Explorer. A portion of its functionality can be seen in pre-release builds, including build 4074, where it is presented as a Buddy Matchmaker feature.
The feature appears in at least one promotional video for the operating system—AERO Feel—as a Play with buddies option in the Details Pane of Windows "Longhorn," but no description for the feature is given.
Friendly Fire was notably mentioned in Maximum PC Magazine by Thomas L. McDonald in an interview with Microsoft's Dean Lester, who was then the company's General Manager of Graphics and Gaming Technologies: "Microsoft plans to integrate its Instant Messenger with the games folder, so that you can see which of your IM buddies have a certain game, and invite them to play, all within a single interface."
The feature was scrapped after the development reset of Windows Vista and Windows Messenger was deprecated in favor of Windows Live Messenger.