Valve's Steam Deck is a Linux-based gaming handheld, and the Linux distribution that it's based on is Arch Linux. It's a lightweight Linux distro that Valve has built a lot on top of, and while the company has never publicly said why exactly it uses Arch, that lightweight nature is probably the biggest reason. However, there are a few other reasons, too.

4 Arch Linux's rolling release model is perfect for Steam OS

Valve can incorporate changes whenever

One of the best parts of Arch Linux for any developer building on top of it is that it has no major release versions. Unlike traditional operating systems that follow a fixed release cycle (with major versions launching every few months or years), Arch Linux continuously provides small, frequent updates to its software packages. This means that Valve can continue to build on Arch Linux while incorporating smaller changes as they come, rather than needing to rebase on top of a major release that Arch releases.

How Arch Linux installs are kept up to date is by updating individual components of the software that compromises the operating system. In other words, you never need to worry about doing a big update, and your regular software updates will keep your isntallation up to date. For Valve, that also means they can pick and choose things they want to incorporate super easily. Valve said as much in an interview with PC Gamer, when quizzed on why the company stopped using Debian for Steam OS.

So, Arch Linux, one of the main reasons, there's a couple, but the main reason is the rolling updates of Arch allows us to have more rapid development for SteamOS 3.0.

Due to the nature of the Steam Deck, the ability to roll out lots of small updates as time goes on is incredibly appealing, and means that development work Valve does will always be on the latest version of the operating system that the hardware is using. Arch essentially ships as close to upstream as possible, meaning that there aren't changes going on that aren't in the latest verison of the operating system.

3 Better performance, even with Proton

Arch is lightweight, giving better performance

One very interesting part of Arch Linux that Valve clearly loves is just how lightweight it is. Even though most games are running through a translation layer in the form of Proton, you can still get better performance in those games on Linux than you can in those games running natively on Windows. Elden Ring is an example of a game that runs better through Proton than it does on Windows on the Steam Deck.

Without Arch Linux being so lightweight, there would be many more games that the Steam Deck wouldn't be capable of playing. Arch Linux enables a lot of what makes the Steam Deck possible, and it makes sense that Valve would sponsor the development of it so that the operating system gets better and better for its own hardware. As a byproduct, that benefits the community too, so it's a win-win for everyone.

2 Arch is free, and Valve pays no licensing

Supporting communities is better for everyone

Valve is one of the few companies that seems to understand when giving back to a community is expected, and Arch Linux definitely feels like something Valve has benefit hugely from. Given the runaway success that the Steam Deck has been, it wouldn't be out of the realms of possibility that Valve felt that to avoid scrutiny in the future or even community backlash, it might be time to start giving back.

Of course, Valve also has a history of, generally, being pretty consumer friendly. Even only recently did the company remove a forced arbitration agreement from its Steam Subscriber Agreement. While there were reasons behind it that benefit Valve as well, it's a consumer friendly move that practically no other companies have made. Given that it's clear Valve still thinks about itself relative to its own community, it would make sense that there may have been a conversation about making sure the company is seen to be giving back to the operating system that powers its most popular hardware.

Given how rich Valve is, along with the fact that Arch is free, it just makes sense that the company figured it would just sponsor the developers of Arch. Again, everyone wins, because Valve knows that the developers at Arch are committed, and the developers get backing for two projects that have been deemed critical; a build service infrastructure and a secure signing enclave.

1 Cross-platform potential

Arm is on the rise

Gaming on Arm is becoming more and more of a reality, and Valve is definitely cooking up something to do with Proton and Arm. A while ago, an Arm version of Proton was spotted in development on SteamDB, and Arm is lauded for its efficiency benefits that are hard, if not impossible, to achieve on x86. Arch Linux can be compiled for Arm, and a port existed for quite a while that was maintained up until the end of last year. While things have been incredibly quiet on that front ever since, it's clear that development for Arch on Arm could happen. Plus, if Valve is already sponsoring critical projects, there's nothing stopping Valve sponsoring an Arm port of Arch in the future.

Given the open-source and cross-platform nature of Arm, sponsoring the project could well be a long-term investment, too. There's a lot of cross-platform potential in a project like Arch Linux, and given it's already been ported to Arm before, it's very likely it could be and maintained again in the future.