Pango Text Layout Library

Pango is a library for laying out and rendering text, with an emphasis on internationalization and multilingual text support. Originally developed by Owen Taylor at Red Hat in 2000 as part of the GTK project, Pango has become the standard text layout engine for Linux desktop environments and is used by GTK, GNOME, LibreOffice, and many other applications. Key features include: internationalized text (full Unicode support with bidirectional text rendering for Arabic, Hebrew, and other RTL languages, complex text layout for Indic, Thai, Tibetan, and Khmer scripts, and vertical text layout for CJK and Mongolian), font handling (integration with FreeType, Fontconfig, HarfBuzz, and CoreText for cross-platform font discovery, loading, and shaping), HarfBuzz integration (using HarfBuzz for OpenType font shaping including ligatures, contextual alternates, kerning, and advanced typographic features), markup and attributes (rich text markup with Pango Markup Language for bold, italic, font size, color, background, strikethrough, underline, superscript, subscript, and custom attributes), layout engine (line breaking, word wrapping, ellipsization, justification, and paragraph layout with configurable alignment, indent, spacing, and margins), context analysis (language detection, script itemization, and font fallback for mixed-script text with per-script font selection), tab positioning (configurable tab stops with left, right, center, and decimal alignment), shaped glyphs (converting Unicode codepoints to positioned glyph indices with advances, offsets, and clusters for proper rendering), rendering backends (Cairo, Xft, Win32, and CoreText rendering integration for cross-platform output), font metrics (ascent, descent, width, height, and character extents for precise text measurement), and PangoContext and PangoLayout (high-level API for creating, configuring, and rendering text layouts with full control over font description, language, direction, and attributes).