PC gamers can share their Steam game library with their friends and family very soon. Once authorized a shared computer, they can earn their own Steam achievements and save their own game progress to the Steam cloud. The process is very simple. See a friend or family member's installed game that you want to play? Send them a request to authorize the computer. Once authorized, the lender's library of Steam games become available for others on the machine to access, download and play.
Game sharing feature is in beta testing currently. if you are interested then join the Family Sharing group. Read FAQ for more information.