Translations by Osama Khalid

2008-02-16

Instructions on how to install and uninstall software, including information on package management.

Credits and License

This document is maintained by the Ubuntu documentation team (https://wiki.ubuntu.com/DocumentationTeam). For a list of contributors, see the <ulink url="../../libs/C/contributors.xml">contributors page</ulink>

This document is made available under the Creative Commons ShareAlike 2.5 License (CC-BY-SA).

You are free to modify, extend, and improve the Ubuntu documentation source code under the terms of this license. All derivative works must be released under this license.

This documentation is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE AS DESCRIBED IN THE DISCLAIMER.

A copy of the license is available here: <ulink url="/usr/share/ubuntu-docs/libs/C/ccbysa.xml">Creative Commons ShareAlike License</ulink>.

Ubuntu Documentation Project

Canonical Ltd. and members of the <placeholder-1/>

This section discusses how applications are installed, removed and kept up-to-date. Also covered are how packages are stored by Ubuntu and made available for download.

How is software installation on Ubuntu different from on Windows?

Ubuntu handles software installation in a very different way to Windows.

If you want to install an application on Windows, you must normally buy a CD containing the software, or download an installer package from the Internet. You then run the installer program, which guides you through the installation process.

On Ubuntu, you simply open a <emphasis>package manager</emphasis>, search for the application that you want and click a button to install it. Removing an application is just as simple.

The package manager downloads applications from a <emphasis>software repository</emphasis>, which is a location on the Internet which stores a collection of applications. These applications come bundled in <emphasis>packages</emphasis>, which contain all of the information needed for installation. You can download packages yourself, using your web browser, if you like, but it is generally much more convenient to let the package manager handle this for you.

Some packages depend on other packages being installed in order to work. For example, a word processing package may require a printing package to be installed. The package manager automatically installs these <emphasis>dependencies</emphasis> for you.

By default, only applications from the official Ubuntu software repositories are available in your package manager. If you cannot find the application that you want in the default repositories, you can add other (<quote>third-party</quote>) repositories and install it from there.

Installing an application

For more information about using the <application>Ubuntu Software Center</application>, consult the <ulink type="help" url="ghelp:software-center">Ubuntu Software Center Manual</ulink>.

Other methods of installing applications

Using Synaptic Package Manager

Synaptic can be used to manage advanced software packages (such as server applications) which Software Center does not manage.

Click <menuchoice><guimenu>System</guimenu><guimenuitem>Administration</guimenuitem><guimenuitem>Synaptic Package Manager</guimenuitem></menuchoice>. Enter your password if prompted.

Click <guibutton>Search</guibutton> to search for an application, or click <guibutton>Sections</guibutton> and look through the categories to find one.

Right-click the application that you want to install and select <guilabel>Mark for Installation</guilabel>.

If you are asked if you would like to mark additional changes, click <guibutton>Mark</guibutton>.

Select any other applications that you would like to install.

Click <guibutton>Apply</guibutton>, and then click <guibutton>Apply</guibutton> in the window that appears. The applications that you chose will be downloaded and installed.

Downloading and installing a .deb package

You can download and install applications from websites. These applications are contained in Debian (.deb) packages. To install a Debian package:

Download the package from a website.

Double-click the package. It will be opened in the Package Installer.

Click <guibutton>Install</guibutton> to install the package.

Installing single packages in this way is not recommended, for the following reasons:

The packages have not been checked for security by Ubuntu members, and could contain software which harms your computer. You should only download single packages from websites that you trust.

The package may require some extra software to run, which cannot be installed automatically. You will have to find and install this software yourself.

Clicking a link on a web page

Some web pages have links which install applications when you click them. These are known as <quote>apt:</quote> links. After clicking the link, you will be asked if you would like to install additional software. Click <guibutton>Install</guibutton> to start the installation process.

The application can only be downloaded and installed if it is available in a software repository which is currently enabled on your computer. This means that websites cannot trick you into installing software which is potentially harmful to your computer.

Removing an application

Click <menuchoice><guimenu>Applications</guimenu><guimenuitem>Ubuntu Software Center</guimenuitem></menuchoice>.

In the <emphasis>Installed Software</emphasis> section, find the application that you want to remove by finding it in the list or by searching for it.

If the application that you want to remove is not available in the <application>Ubuntu Software Center</application>, use Synaptic (<menuchoice><guimenu>System</guimenu><guimenuitem>Administration</guimenuitem><guimenuitem>Synaptic Package Manager</guimenuitem></menuchoice>) to remove it instead.