https://wccftech.com/steam-deck-dev-kit-os-leaked-new-steamos-3-screenshots-revealed/

The Steam Deck development kit has been distributed to game developers earlier this week. However, according to SteamDB creator Pavel Djundik, the dev kit has been leaked. Thus, we're able to see some neat features about the upcoming handheld made by Valve such as the Deck's Operating System and UI.

Let's start with the Operating System. The Steam Deck will come equipped with SteamOS 3.0. This new version of the company's Linux-based platform shares similarities to the Windows app. These similarities seem to be a departure from the original SteamOS which was aiming to be more of a propietary OS from Valve.