Backends

A backend is the native executable that hosts a browser (or windowing) engine and implements the C ABI. laufey ships three; a fourth is on a branch. All implement the same laufey_backend_api_t, so a runtime is portable across them — the differences are in engine, process model, size, and a few features that a given engine can’t express on a given OS (see the feature pages).

Platform support is x86_64 + aarch64 on macOS and Linux, x86_64 on Windows. Android is not supported.

CEF

Embeds Chromium 144 through the Chromium Embedded Framework and runs Chromium’s real multi-process architecture — a browser process plus renderer, GPU, and utility subprocesses, with the same rendering and DevTools you get in Chrome. The engine is bundled into the app, so binaries are large but rendering is identical everywhere and independent of the host OS.

Sources live in cef/; shared native features come from backend-common. On Windows the backend links the static CRT (/MT), so everything it links — including backend-common — is built /MT.

Linux caveat: the application menu doesn’t work under CEF (a GtkMenuBar must be packed into a GtkWindow above the browser, and reparenting CEF into a client-owned GtkWindow via CefWindowInfo::SetAsChild breaks on XWayland). Context menus do work, because GtkMenu popups need no GtkWindow container.

WebView

Delegates to the platform’s native web engine — WKWebView on macOS, WebView2 on Windows, WebKitGTK on Linux. The engine is never bundled, so apps stay small, at the cost of rendering that varies by OS and engine version. Single-process.

Sources live in webview/, one file per platform (webview_macos.mm, webview_windows.cc, webview_linux.cc), sharing backend-common for menus, tray, dialogs, dock, and notifications.

Winit

Engine-free. It creates native windows via winit for apps that draw their own content — GPU surfaces, custom renderers — without loading a web engine. There is no JS bridge; get_window_handle / get_display_handle expose the raw handles needed to create a rendering surface. Sources in winit/.

Servo (experimental)

A Servo-based backend is preserved on the servo branch for future work and is not part of the mainline build.

backend-common

CEF and WebView share their native-API implementations (menus, tray, dock, dialogs, notifications, key mapping) in backend-common/, included as a CMake subdirectory by each backend. The winit backend shares its non-engine pieces through backend-winit-common instead.