The Assistive Technology Service Provider Interface, core components, is part of the GNOME accessibility project.

Pango is a library for laying out and rendering text, with an emphasis on internationalization. Pango can be used anywhere that text layout is needed, but using Pango in conjunction with Cairo and/or Gtk2 provides a complete solution with high quality text handling and graphics rendering.

Dynamically loaded modules handle text layout for particular combinations of script and font backend. Pango provides a wide selection of modules, including modules for Hebrew, Arabic, Hangul, Thai, and a number of Indic scripts. Virtually all of the world's major scripts are supported.

In addition to the low level layout rendering routines, Pango includes Pango::Layout, a high level driver for laying out entire blocks of text, and routines to assist in editing internationalized text.

Guile-RSVG wraps the RSVG library for Guile, allowing you to render SVG images onto Cairo surfaces.

Cairomm provides a C++ programming interface to the Cairo 2D graphics library.

libdbusmenu passes a menu structure across DBus so that a program can create a menu simply without worrying about how it is displayed on the other side of the bus.

GtkSourceView is a text widget that extends the standard GTK+ text widget GtkTextView. It improves GtkTextView by implementing syntax highlighting and other features typical of a source code editor.

GTKmm is the official C++ interface for the popular GUI library GTK+. Highlights include typesafe callbacks, and a comprehensive set of widgets that are easily extensible via inheritance. You can create user interfaces either in code or with the Glade User Interface designer, using libglademm. There's extensive documentation, including API reference and a tutorial.

GTK+, or the GIMP Toolkit, is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off tools to complete application suites.

Guile-Present defines a declarative vocabulary for presentations, together with tools to render presentation documents as SVG or PDF. Guile-Present can be used to make presentations programmatically, but also includes a tools to generate PDF presentations out of Org mode and Texinfo documents.

GtkDoc is a tool used to extract API documentation from C-code like Doxygen, but handles documentation of GObject (including signals and properties) that makes it very suitable for GTK+ apps and libraries. It uses docbook for intermediate files and can produce html by default and pdf/man-pages with some extra work.

Gromit-MPX is an on-screen annotation tool that works with any Unix desktop environment under X11 as well as Wayland.

Libpanel provides a library to create IDE-like applications using GTK and libadwaita. It has widgets for panels, docks, columns and grids of pages. Primarily, its design and implementation focus around the GNOME Builder and Drafting projects.

gtksourceviewmm is a portable C++ library that extends the standard GTK+ framework for multiline text editing with support for configurable syntax highlighting, unlimited undo/redo, search and replace, a completion framework, printing and other features typical of a source code editor.

Cairo is a 2D graphics library with support for multiple output devices. Currently supported output targets include the X Window System (via both Xlib and XCB), Quartz, Win32, image buffers, PostScript, PDF, and SVG file output. Experimental backends include OpenGL, BeOS, OS/2, and DirectFB.

Guile-Present defines a declarative vocabulary for presentations, together with tools to render presentation documents as SVG or PDF. Guile-Present can be used to make presentations programmatically, but also includes a tools to generate PDF presentations out of Org mode and Texinfo documents.

PNMixer is a simple mixer application designed to run in system tray. It integrates nicely into desktop environments that don't have a panel that supports applets and therefore can't run a mixer applet. In particular, it's been used quite a lot with fbpanel and tint2 but should run fine in any system tray.

PNMixer is designed to work on systems that use ALSA for sound management. Any other sound driver like OSS or FFADO are, currently, not supported. There is no official PulseAudio support, at the moment, but it seems that PNMixer behaves quite well anyway when PA is running.

GooCanvas is a canvas widget for GTK+ that uses the cairo 2D library for drawing.

GTK+, or the GIMP Toolkit, is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK+ is suitable for projects ranging from small one-off tools to complete application suites.

GdkPixbuf is a library that loads image data in various formats and stores it as linear buffers in memory. The buffers can then be scaled, composited, modified, saved, or rendered.

Volume Icon is a volume indicator and control applet for the Advanced Linux Sound Architecture. It sits in the system tray, independent of your desktop environment, and supports global key bindings.

GTK is a multi-platform toolkit for creating graphical user interfaces. Offering a complete set of widgets, GTK is suitable for projects ranging from small one-off tools to complete application suites.

The Assistive Technology Service Provider Interface, core components, is part of the GNOME accessibility project.

Guile-Cairo wraps the Cairo graphics library for Guile Scheme. Guile-Cairo is complete, wrapping almost all of the Cairo API. It is API stable, providing a firm base on which to do graphics work. Finally, and importantly, it is pleasant to use. You get a powerful and well-maintained graphics library with all of the benefits of Scheme: memory management, exceptions, macros, and a dynamic programming environment.

Layer Shell is a Wayland protocol for desktop shell components, such as panels, notifications and wallpapers. It can be used to anchor windows to a corner or edge of the output, or stretch them across the entire output. It supports all Layer Shell features including popups and popovers.