You can bet the entire industry will watch how this plays out. From the outset, Valve is taking it step by step:
Steam Family Sharing, a new service feature that allows close friends and family members to share their libraries of Steam games, is coming to Steam, a leading platform for the delivery and management of PC, Mac, and Linux games and software. The feature will become available next week, in limited beta on Steam.
Steam Family Sharing is designed for close friends and family members to play one another’s Steam games while each earning their own Steam achievements and storing their own saves and application data to the Steam cloud. It’s all enabled by authorizing a shared computer.
“Our customers have expressed a desire to share their digital games among friends and family members, just as current retail games, books, DVDs, and other physical media can be shared,” explained Anna Sweet of Valve. “Family Sharing was created in direct response to these user requests.”
Once a device is authorized, the lender’s library of Steam games becomes available for others on the machine to access, download, and play. Though simultaneous usage of an account’s library is not allowed, the lender may always access and play his games at any time. If he decides to start playing when a friend is borrowing one of his games, the friend will be given a few minutes to either purchase the game or quit playing.
For me at least, this gives a chance for my Steam buddies to play a significant amount of titles sitting in my Steam list which I’ve never installed, much less played.
Devices for the sharing service is limited to ten with only one person being able to play the game at a time. Region restrictions will still apply.
A word of warning though: make sure the people you are sharing your games with are trustworthy as your privileges may be revoked if your friend turns out to be an aimbotter.
More info on the beta can be found here.