Perhaps Valve’s crusade against Windows isn’t quite over yet. After Valve quietly removed the Steam Machines page from its storefront earlier this year, it seemed like a quiet capitulation to Windows 10. Maybe Valve’s tactics have changed though, as evidenced by details datamined by the /r/linux_gaming subreddit (via Ars Technica) this week: Steam Play, a WINE-like compatibility wrapper.

First, let’s talk WINE. Standing for “WINE Is Not an Emulator,” the open-source software attempts to cajole Windows executables into running on Unix-based systems, i.e. Mac or Linux. Straight from the WINE website, “Instead of simulating internal Windows logic like a virtual machine or emulator, Wine translates Windows API calls into POSIX calls on-the-fly, eliminating the performance and memory penalties of other methods.”

With fairly simple programs it’s pretty solid. With games? It’s more complicated. There’s a Steam curator dedicated to WINE-compatible games, multiple websites (including part of WINE’s) dedicated to the same, and so on. There are also people working on projects alongside WINE, like dxvk, which translates DirectX 11 to Vulkan. Those have their own compatibility lists. Often compatibility lags behind releases by a year or two, especially on big-budget games. A few never work at all.

In any case, it sounds like Valve is creating its own wrapper, Steam Play, and integrating it into Steam or at least SteamOS, its Linux fork. Settings found this week include options to “Enable Steam Play for supported titles,” “Enable Steam Play for all titles,” “Steam Play will automatically install compatibility tools that allow you to play games from your library that were built for other operating systems,” and “Steam Play FAQ.”

That “Supported Titles/All Titles” divide is interesting, as it suggests that like WINE, there will be games that work perfectly with Steam Play and games that won’t. Indeed, another text string notes that forcing compatibility on untested titles “may not work as expected, and can cause issues with your games, including crashes and breaking save games.”

It’s not a one-size-fits-all fix in other words, and definitely not a sign that Linux gaming will supplant Windows anytime soon. Those already running Linux or MacOS could benefit from a Valve-backed and gaming-oriented compatibility wrapper though, and that in turn might make SteamOS more attractive—or indeed, a second generation of Steam Machines, if for some reason Valve has that in mind. You never know.