While Steam’s user interface isn’t open source, nor are most of the games, the experience wouldn’t be possible without an entire stack of free and open-source technology underneath. Valve knows this, and they’re paying numerous developers to improve the technologies they depend on.
So what are the technologies that the Steam Deck utilizes to deliver an experience that has impressed much of the gaming world?
1. Arch Linux
The Steam Deck comes with an operating system known as SteamOS. SteamOS differs from the operating systems you’re most likely to see on PCs in stores—Windows, macOS, and ChromeOS. It’s based on Linux, an OS that consists of code that people can legally share or utilize to create their projects.
There are many ways to configure and distribute a Linux-based OS. Valve uses an existing distribution known as Arch Linux. What sets Arch apart from other well-known Linux distributions is the freedom provided to assemble components however you wish to create a functional desktop, and the ability to download new software as soon as it is available.
Arch Linux requires a degree of technical understanding to install and use, and the rolling nature of its continuous updates means parts of the interface can break. So SteamOS uses a read-only version of Arch, where Valve creates a stable working version that it can test before shipping an exact copy of that version to Steam Deck owners.
Vulkan is an open standard for rendering 3D graphics. There are various standards floating around. On Windows, the most well-known standard is Microsoft’s Direct3D. Direct3D is part of DirectX, a closed-source collection of multimedia APIs all exclusive to Microsoft Windows.
Unlike Direct3D, Vulkan is open-source and cross-platform. This makes it available for use across a wide range of architecture, including Apple devices and the Nintendo Switch.
One goal of the Vulkan project is to deliver high performance while putting less strain on both the CPU and GPU (specifically compared to OpenGL, another cross-platform, open standard). This allows lower-powered mobile hardware to handle more graphically impressive games while offering better battery life.
Mesa is a vital part of the chain between 3D graphics being generated and the visuals actually appearing on your screen. Mesa translates Vulkan code into something your hardware can understand.
Intel and AMD are two of the largest users of Mesa. Both companies produce open-source graphics drivers for their hardware that utilizes Mesa. Intel only utilizes Mesa, whereas AMD offers Mesa as its open-source option and a separate proprietary driver known as Catalyst.
Valve partnered with AMD to create Steam Deck’s APU. An APU is an alternative to having a separate CPU and GPU, enabling a system to more efficiently handle data.
Mesa isn’t only relevant for gaming. Modern display servers for Linux use OpenGL to display your desktop interface. So all graphics, whether in-game or navigating your Steam Deck’s desktop mode, utilize Mesa.
4. Proton (and Wine)
Proton is a compatibility layer that enables games developed for Windows to run on Linux-based OSes. Valve develops Proton in collaboration with CodeWeavers. But these two companies didn’t create Proton from scratch. Proton is a fork of Wine, a compatibility layer designed to enable general-purpose Windows software to run on Linux.
Linux users have long used Wine to play Windows games. The challenge has been configuring Wine in precisely the right way for each game to run.
Since Proton’s focus isn’t on apps like Microsoft Office or Photoshop, development efforts can prioritize gaming-specific technologies that improve performance and enable more games to work out of the box.
Thanks to Proton, a substantial proportion of your Steam library can run on the Steam Deck even though most games were not designed to run on a Linux-based platform. This includes many of the games that are Deck Verified.
5. KDE Plasma
You could easily walk away with the impression that Valve designed its own desktop mode for the Steam Deck. The interface resembles Windows, except there’s a Steam Deck icon in the bottom left instead of a Windows logo. But the more you look around, the more differences you find.
Valve didn’t actually design the Steam Deck’s desktop, nor is the interface intended to be a copy of Windows. Instead, the interface you’re looking at is known as KDE Plasma. It’s a desktop environment for free and open-source operating systems.
KDE has been around since 1996, and if you like, you can easily install KDE on your laptop or desktop. These days, you can even put KDE on certain phones and televisions.
Flatpak is a package format for distributing apps on Linux that is capable of running on the majority of distributions. This includes distributions like SteamOS that aren’t intended to serve as general-purpose operating systems.
If you switch to Steam Deck’s desktop mode, Flatpak is the easiest and most reliable way to get apps onto your machine. You can download many of the apps you might want from a site known as Flathub. In fact, the Discover app store that comes preinstalled on the Steam Deck downloads apps from Flathub by default.
You can look through apps on your Steam Deck, but you can also browse Flathub in a web browser. This lets you get an idea of what apps are available for Valve’s dockable PC out of the box.
The Steam Deck Is a Relatively Open Device
To be clear, much of the software powering the Steam Deck is closed-source, but the device depends a great deal on open-source technologies. And unlike other consoles that utilize or base themselves on an open-source OS, you can actually access the Linux underpinnings.
You can use your Steam Deck as a Linux PC or install games from sources other than Steam. Valve’s open approach, and willingness to invest in open code is part of what has made the Steam Deck into what it has become.