Steam has its library UI redesign up and running in beta form, but today it is ready for everyone. The Steam client is now rolling out the new library to everyone.
This time, the right side of the screen is more useful and dynamic than before. If games recently have updates or are having an in-game event running, those will be bumped up for the player to know. But if you just want to just play that one game you last played again, Steam makes it easy for you to find the big green play button. It also highlights games your friends in the friends list are playing recently too.
But the coolest part is how the games are now laid out on the main screen. You can create custom shelves, similar to adding categories. But you can also make a dynamic shelf where it automatically populates with games in the tags you requested. The handiest of all is having a shelf highlighting all the games you have installed and ready to go.
You can check out the blog post on Steam for the full list of features. The new Steam library should be live for everyone as soon as the latest update is installed.