Steam letting users share their game libraries has been suggested before as a possibility, and it puts a smile on my face to see that we're finally getting the feature. With Family Sharing, you can share your Steam library with up to 10 authorized devices at a given time, earn your own achievements, and save your personal in-game progress to the cloud. Here's Valve's explanation of how the system will work when it rolls out for everyone:
"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."
Not all games will be sharable -- those which require a third-party key, account, or subscription to play are cited as examples -- but this is another one of those features that's great to see implemented. Valve will launch a beta for Family Sharing next week. Go sign up!