under the GNU General Public License (GPL).
In 2001 Qt 3.0 was released. Qt 3.0 was a huge step forward over Qt 2. Qt now contained
over half a million lines of code and contained 42 new classes over Qt 2. Qt 3 did not
provide support for embedded development.
In 2005 Qt 4 was launched which is the version that is still in development today. Qt 4
gained a new modular approach to application development, and added renewed support
for embedded platforms. More about the Qt 4 modules in section 2.1.2.
Current well known solutions using Qt 4 are KDE, Google Earth, Autodesk Maya and Skype.
2.1.2 Qt 4 Features
Qt 4 has brought an enormous amount of improvements over Qt 3. Notably the split into
several modules  . Currently the following modules exist:
QtCore - Themain Qt module. This module contains all basicclasses in Qt. Examples
are QCoreApplication, QList and QString.
QtDeclarative - The module containing classes for use with the Qt Declarative Markup
Language (QML). The features provided by this module will be used in this project.
QtDeclarative is a new module, rst included in Qt 4.7.
QtGui - The QtGui module contains classes for creating GUI applications. Classes
for using the Graphicsview framework, QWidgets, toolbars, etc. can be found in this
QtMultimedia - QtMultimedia is a module introduced with Qt 4.6. This module gives
the developer low-level access to the multimedia hardware in a device.
QtNetwork - QtNetwork makes it possible to create networked applications like web
servers and clients.
QtOpenGL - The module containing convenience API for developing OpenGL appli-
cations. There is a QGLWidget class that provides the developer with a surface to
use for OpenGL rendering.
QtSql - QtSql is a bridge for using database systems. There exist several database
plugins for QtSql: MySQL, PostgreSQL, SQLite and others.
QtSvg - Module that allows the loading of SVG vector graphics images.
QtTest - The QtTest module is a convenience library to write unittests for a Qt
QtWebKit - Module containing the Qt version of the WebKit web browser engine.
QtXml - XML handling module. Makes parsing and editing XML documents possible.
Phonon - High-level multimedia handling module. This module uses plugins called
backends to play multimedia content. There are several backends including: Direct-
Show, Quicktime and GStreamer.
Qt3Support - Convenience module for developers porting their applications from Qt
3to Qt 4.
During the lifetime of Qt 4 several new important technologies have been added . These
The Graphicsview framework - This framework provides somethingsimilar toa painters’
canvas where the developer can lay-out images and text.