User interface and display

GTK+

Widget toolkit for graphical interfaces

GDK

Low-level abstraction for the windowing system

Cairo

2D, vector-based drawing for high-quality graphics

Pango

International text rendering with full Unicode support

Clutter

Animations and scene graph

WebKit

HTML5 web page rendering

ATK

Accessibility toolkit to implement support for screen readers and other tools

Storage of the user's data

Evolution Data Server

Desktop-wide addressbook for contacts and calendar

GSettings

Configuration storage for application preferences

Keyring

Secure storage for passwords and other data

GDA

Unified access to relational databases

Tracker

Storage and retrieval for document metadata

File access

GIO Files

File and URI handling, asynchronous file operations, volume handling

Networking

GIO Networking

Networking and sockets API with streams.

Libsoup

Asynchronous HTTP library with cookies, SSL, and XML-RPC

Avahi

Zeroconf service discovery on local networks

GUPnP

Wireless, peer-to-peer, plug-and-play RPC

NetworkManager

Manage network connections and monitor online/offline status

Application support

Help

Topic-oriented online help system

Enchant

Real-time spell checking for text widgets

PackageKit

Software installation and management

Libnotify

Interactive notifications in the desktop's message tray

Poppler

PDF rendering

Telepathy

Unified instant-messaging and communications service

Multimedia

Canberra

Simple audio API for notifications and events

GStreamer

Playing, mixing, and manipulating sound and video

Rygel

Network multimedia framework

PulseAudio

Low-level audio API

Inter-process communication

D-Bus

Inter-process communication bus to provide APIs to other processes

PolicyKit

Access control for system-level services provided through D-Bus

Low-level framework

GLib

Data structures and utilities for C programs

GObject

C-based object and type system with signals and slots

Geographical

Geocode-glib

Geolocation

Champlain

Map rendering

Low-level system interfaces

UDisks

Low-level operations on disks and volumes

UPower

Interface to the system's power manager