Games for Windows – Live (trademarked as Games for Windows – LIVE) is an online gaming service used by Games for Windows–branded PC titles that enables Windows PCs to connect to Microsoft's Live service. Users, each with a unique Gamertag (the Microsoft username service for gaming that began on Xbox Live) are able to play online, keep track of their friends' status, send and receive messages, gain and keep track of Achievements and associated Gamerscore, voice chat across platforms, and much more. Some games allow for cross-platform play, such as Shadowrun, putting Windows players against Xbox 360 players.