kageroumado Releases Sevoflurane Beta, Bringing Windows Steam Games to Apple Silicon Macs as Native Mac Apps

On September 30, 2026, kageroumado released the first public beta of Sevoflurane, a free and open-source application that plays Windows Steam games on Macs with Apple silicon. Sevoflurane presents Steam and each game as a genuine Mac application, with native windows, menus, notifications and Dock icons.

The Windows Steam client runs hidden inside Wine. Sevoflurane opens Steam's web-based interface in native WebKit windows at full Retina resolution and connects them to the client, so the library, store, friends list, chats and the in-game overlay each appear as a Mac window, with Steam's menus in the macOS menu bar and its alerts delivered as Mac notifications.

Every game launches as its own Mac application with its own name and Dock icon, which allows macOS to engage Game Mode automatically when the game fills the screen. Games with a fixed window size, including older titles, become freely resizable and support native full screen. Optional upscaling renders the picture beyond the game's own resolution, using Lanczos filtering by default, Apple's MetalFX for 3D games, and anime-specific neural upscalers (Anime4K, CuNNy) for visual novels and 2D art.

Games run on Dormison, kageroumado's own build of Wine based on upstream wine-staging, which hosts DirectX 12 through D3DMetal from Apple's Game Porting Toolkit. CrossOver is also supported as an engine. Windows programs outside Steam open directly from Finder, and HoYoverse titles including Genshin Impact, Honkai: Star Rail and Zenless Zone Zero install and update from HoYoverse's own servers.

Key features

• Steam's library, store, friends and chats in native Retina Mac windows
• Each game as its own Mac app with a Dock icon and automatic Game Mode
• Resizable windows and native full screen for fixed-size games
• Optional upscaling: Lanczos, MetalFX, Anime4K and CuNNy
• DirectX 12 via D3DMetal on the Dormison Wine engine
• Windows programs and installers outside Steam, opened from Finder

Availability

Sevoflurane 1.0 beta 1 is available now as a free download from kagerou.glass/sevoflurane and GitHub. It requires macOS 26 or later on a Mac with Apple silicon. The source code is published under the MIT License.