Overview of GTK and its Libraries

Over time GTK has been built up to be based on various libraries, also developed by the GTK team.

GDK

GDK is the GTK windowing system abstraction; it provides the minimum common API surface for writing GTK on top of various platforms, like Wayland and X11 on Linux and Unix-like systems; Microsoft Windows; and Apple macOS.

GSK

GSK is the GTK rendering abstraction; it provides a low level rendering API to GTK in terms of draw operations, and converts them into commands for the graphics pipeline.

GLib

GLib is a low-level core library that forms the basis of GTK. It provides data structure handling for C, portability wrappers and interfaces for such run-time functionality as an event loop, threads, dynamic loading and an object system.

Pango

Pango is a library for layout and rendering of text with an emphasis on internationalization. It forms the core of text and font handling for GTK.

GdkPixbuf

GdkPixbuf is a library for loading graphical assets like icons in various formats, like PNG, JPEG, and GIF. GdkPixbuf is extensible through dynamically loaded modules, which can be written and maintained independently from the main library.

Cairo

Cairo is a library for 2D graphics with support for multiple output devices (including the X Window System, Win32) while producing a consistent output on all media while taking advantage of display hardware acceleration when available.

Graphene

Graphene is a library providing efficient types for 2D and 3D maths.

HarfBuzz

HarfBuzz is a text shaping library. Using the HarfBuzz library allows programs to convert a sequence of Unicode input into properly formatted and positioned glyph output—for any writing system and language.