xft

Xft, short for X FreeType, is a font rendering library used by the X Window System to display scalable, anti-aliased text. It uses the FreeType font rasterizer and the fontconfig library to select fonts and render glyphs, providing high-quality typography with hinting and subpixel rendering for LCDs. Xft works with the X Render extension to composite antialiased text into the display.

The library exposes font objects such as XftFont and drawing utilities such as XftDraw, and it expects applications to query fonts via fontconfig patterns, then render glyphs through FreeType. The typical pipeline goes from font discovery (by family, style, weight, and size) through rasterization to anti-aliased bitmap glyphs drawn on an X drawable. Xft supports Unicode and advanced typography features provided by FreeType, including hinting and subpixel layout.

History and role: Xft emerged in the late 1990s as part of the X.Org project to provide modern font rendering for X11, replacing older bitmap fonts. It established a standard interface for font rendering in many X11 clients and toolkits and integrates with fontconfig to enable consistent font matching across applications.

Current status: Xft remains a foundational component of the X11 rendering stack and is maintained within the X.Org ecosystem. In modern desktop deployments, font rendering often involves higher-layer toolkits (such as Pango/Cairo) or Wayland-based rendering, but many X11 applications continue to use Xft as their font backend.