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.

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.

Cairo::GObject registers Cairo's types with Glib's type systems, so that they can be used normally in signals and properties.

GtkSheet is a matrix widget for GTK+. It consists of an scrollable grid of cells where you can allocate text. Cell contents can be edited interactively through a specially designed entry, GtkItemEntry. It is also a container subclass, allowing you to display buttons, images and any other widget in it. You can also set many attributes such as border, foreground and background colors, text justification and more.

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.

This package contains the standard GTK+ 2.x theming engines including Clearlooks, Crux, High Contrast, Industrial, LighthouseBlue, Metal, Mist, Redmond95 and ThinIce.

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.

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.

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.

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.

GNU Spread Sheet Widget is a library for Gtk+ which provides a widget for viewing and manipulating 2 dimensional tabular data in a manner similar to many popular spread sheet programs.

ClipIt is a clipboard manager with features such as a history, search thereof, global hotkeys and clipboard item actions. It was forked from Parcellite and adds bugfixes and features.

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.

Pango is a library for laying out and rendering of text, with an emphasis on internationalization. Pango can be used anywhere that text layout is needed, though most of the work on Pango so far has been done in the context of the GTK+ widget toolkit. Pango forms the core of text and font handling for GTK+-2.x.

Pangomm provides a C++ programming interface to the Pango text rendering library.

Dragon is a lightweight drag-and-drop source for X where you can run:

dragon file.tar.gz

to get a window with just that file in it, ready to be dragged where you need it. What if you need to drag into something? Using:

dragon --target

you get a window you can drag files and text into. Dropped items are printed to standard output.

Pangox was a X backend to pango. It is now obsolete and no longer provided by recent pango releases. pangox-compat provides the functions which were removed.

Libdatrie is an implementation of double-array structure for representing trie. Trie is a kind of digital search tree.

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

Webp-pixbuf-loader is a WebP format loader of GdkPixbuf.

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.

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

Pycairo is a set of Python bindings for the Cairo graphics library.

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.