Steam Play brings Windows games to Linux

More than five years after launching its Steam for Linux digital distribution platform Valve has finally added support for non-Linux games, allowing users to install Windows titles via a built-in compatibility tool dubbed Proton.

Steam for Linux launched in February 2013, bringing Valve's popular digital distribution platform off Windows for the first time. Prior to its release, users had been working around the lack of Linux support by installing Steam via the Wine Windows compatibility wrapper; the native Steam client did away with the need for this workaround, but at the cost of only supporting titles that developers had marked as natively supporting Linux. For those with a hefty library of Windows-exclusive titles, the only solution was to keep two copies of Steam installed: One copy of Steam for Linux to install native Linux titles, and one copy of Steam for Windows running via Wine to install native Windows titles.

The updated Steam Play, now available in public beta, does away with this, adding in the ability to play Windows titles directly from the Steam for Linux client. The trick is the same workaround that Linux users have been using since the first Steam for Windows client release, only built in. Proton, Valve explains, is a customised version of the Wine Windows compatibility layer with various tweaks specific to Steam and particular games. When a game is marked as compatible, it appears in the SteamOS & Linux section of the Steam Library with a note that it is playable via Steam Play; users can then install and play the game as though it was a native Linux release.

'Our goal for this work is to let Linux Steam users enjoy easy access to a larger back catalogue,' explains Valve's Pierre Loup. 'We think it will also allow future developers to easily leverage their work from other platforms to target Linux. This would give them the option of focusing on areas that would make a meaningful experience difference for all users instead, such as supporting Vulkan.'

The beta Proton software includes various tweaks over the standard Wine release, including full support for Steamworks and OpenVR, DirectX 11 and DirectX 12 translation to Vulkan for improved performance, full-screen stretching that doesn't alter the desktop resolution, improved game controller support, and better performance for games with multi-threading support.

At present, Valve is enabling the new Steam Play compatibility feature for only a subset of available Windows games: Beat Saber, Bejeweled 2 Deluxe, Doki Doki Literature Club, Doom, Doom VFR, Doom II: Hell on Earth, The Ultimate Doom, Fallout Shelter, Fate, Final Finatasy VI, Geometry Dash, Google Earth VR, Into The Breach, Magic: The Gathering - Duels of the PLaneswalkers 2012 and 2013, Mount & Blade, Mount & Blade: With Fire & Sword, Nier: Automata, Payday: The Heist, Quake, STALKER: Shadow of Chernobyl, Star Wars: Battlefront 2, Tekken 7, The Last Remnant, Tropico 4, Warhammer 40,000: Dawn of War - Dark Crusade and Soulstorm. Compatibility with games not yet whitelisted - a process done manually at Valve, without the publisher or developer needing to be involved - is also available through a settings toggle, which enables the ability to install any Windows title currently available on Steam.

For the initial beta test, Valve has confirmed, Linux users will not be able to purchase Windows games - whitelisted or otherwise - through the Steam for Linux client, nor will they be marked as being compatible with Linux. This will change when the software is marked for full release. Interestingly, while Valve has confirmed that Proton can technically run on Apple's macOS, the company has stated it has no immediate plans to bring the revamped Steam Play to non-Linux platforms.

Those eager to try the software out need only opt into the Steam for Linux beta, enable the new Steam Play compatibility - for whitelisted titles only or all titles - in the Settings screen, and attempt to install a compatible title from their Steam Library. More information is available from the official announcement.