installed, the user must then authenticate through Steam to de-encrypt the executable files to play the game. Normally this is done while connected to the Internet following the user's credential validation, but once they have logged into Steam once, a user can instruct Steam to launch in a special offline mode to be able to play their games without a network connection. Developers are not limited to Steam's CEG and may include other forms of DRM (or none at all) and other authentication services than Steam; for example, some games from publisher Ubisoft require the use of their UPlay gaming service. Other games required Games for Windows – Live, of which many transitioned to using the Steamworks CEG approach following its shutdown in 2014. In November 2007, Steam achievements were added, similar to Xbox 360 Achievements. In September 2008, Valve added support for Steam Cloud, a service that can automatically store saved game and related custom files on Valve's servers; users can access this data from any machine running the Steam client. Games must use the appropriate features of Steamworks for Steam Cloud to work. Users can disable this feature on a per-game and per-account basis. Cloud saving was expanded in January 2022 for Dynamic Cloud Sync, allowing games developed with this feature to store saved states to Steam Cloud while a game is running rather than waiting until the user quit out of the game; this was added ahead of the portable Steam Deck unit so that users can save from the Deck and then put the unit into a suspended state. In May 2012, the service added the ability for users to manage their game libraries from remote clients, including computers and mobile devices; users can instruct Steam to download and install games they own through this service if their Steam client is currently active and running. Product keys sold through third-party retailers can also be redeemed on Steam. For games that incorporate Steamworks, users can buy redemption codes from other vendors and redeem these in the Steam client to add the title to their libraries. Steam also offers a framework for selling and distributing downloadable content (DLC) for games. In September 2013, Steam introduced the ability to share most games with family members and close friends by authorizing machines to access one's library. Authorized players can install the game locally and play it separately from the owning