Wayland

Wayland is a communication protocol that specifies the communication between a display server (called a Wayland compositor) and its clients, designed as a modern replacement for the X Window System (X11). Initiated by Kristian Hognesberg at Intel in 2008, Wayland addresses the fundamental architectural limitations of X11, which was designed in 1984 for a era when all applications ran locally on the same machine. Key improvements over X11 include: simplified architecture (Wayland merges the display server, compositing manager, and window manager into a single compositor process, eliminating the complex X11 client-server protocol with over 300 extension protocols), direct rendering (clients render directly to their own buffers using OpenGL, Vulkan, or software rendering, then hand off the buffer to the compositor for display, reducing latency and overhead), buffer passing model (instead of drawing commands sent over a socket, clients allocate a shared memory buffer or DMA-BUF, draw to it, and pass it to the compositor, enabling zero-copy rendering and GPU buffer sharing), security (each client only sees its own windows and cannot keylog or screenshot other windows, unlike X11 where any application can snoop on all input and screen content), HiDPI support (per-output scale factors and fractional scaling, addressing the blurry text issues of X11), multi-monitor support with independent resolutions and refresh rates, tear-free rendering (the compositor synchronizes buffer swaps to the display refresh rate, eliminating screen tearing), input handling (libinput provides unified input device handling for keyboards, mice, touchscreens, tablets, and trackpads), and XWayland (a compatibility layer that runs X11 applications under Wayland, ensuring legacy applications continue to work). Major Wayland compositors include GNOME Mutter, KDE KWin, Sway, and wlroots-based compositors.