Steam Family Sharing exits beta, Neowin shows you how to set it up
http://www.neowin.net/news/steam-family-sharing-exits-beta-neowin-shows-you-how-to-set-it-up
After many months of beta testing, Valve has made its Steam Family Sharing program available to all Steam users.For those unaware, Steam Family Sharing allows you to share your entire library of games with up to five users spread across ten authorized machines. In almost all cases, playing a shared title offers the exact same experience as playing a game that you’ve purchased yourself. All game progress is still saved via Steam Cloud services and Steam Achievements are earned only by the user actually playing.