Adding, Removing and Updating Applications

Synaptic Package Manager

Sooner or later, you will have the need to install additional programs on your computer. Ubuntu comes with a special tool called Synaptic that will help you with this task. Synaptic is an advanced package management application that can install and remove every package available to your system. It gives you complete control over the package management of your system.

To launch Synaptic, choose Applications->System->Synaptic Package Manager on the desktop menu system.


Running Synaptic requires administrative privileges (see the section called “Root And Sudo”).

The Synaptic screen is divided up into four sections, the two most important being the package categories on the left side, and the packages on the right.

If you know the name of the package, the quickest way to install it is to click on the Search tool bar button, enter the name in the search text field and click the Search button. Synaptic will now show you a short list from which to select your application for installation. This is usually much easier than having to look through the very long list of applications in the category section. Now right click on it and choose "Mark this package for installation". Once you are satisfied with your selections click Apply on the top button bar. Synaptic will then download and install the required packages from the online repositories and/or from your Ubuntu installation CD.

In case you do not know the name of the package, choose section in the lower left part of the window, choose the appropriate category, and find the package name in the list.

When the installation process has finished, you should have a new option for the program you installed available in the menu.

Extra Repositories

Many software packages you might need are not in the Main repository, so let us learn how to add extra repositories.

What are Repositories?

There are thousands of programs available to install on Ubuntu. These programs are stored in software archives (repositories) and are made freely available for installation over the Internet. This makes it very easy to install new programs in Linux, and it is also very secure, because each program you install is built specially for Ubuntu and checked before it is installed. To organise the software, Ubuntu repositories are categorised into four groups: Main, Restricted, Universe, and Multiverse.

The rationale used to determine which software goes into which category is based on two factors:

  • The level of support software development teams provide for a program.

  • The level of compliance the program has to the Free Software Philosophy.

You can find more information about the Repositories available on the website.

The standard Ubuntu Install CD contains some software from the Main and Restricted categories. Once your system is made aware of the Internet-based locations for these repositories, many more software programs are made available for installation. Using the software package management tools already installed on your system, you can search for, install and update any piece of software directly over the Internet, without the need for the CD.

Adding Extra Repositories

To enable the extra repositories:

  1. Open Applications->System->Software Properties.

  2. Select Add

  3. To enable the Universe repository, check the Community Maintained (Universe) button.


    Adding this repository will mean that the majority of the Free Software universe will be available to install on your system. This software is supported by a carefully selected group of volunteers within the Ubuntu Community, but is not supported by the core Ubuntu development team and may not include security updates.

  4. To enable the Multiverse repository, check the Non-free (Multiverse) button.


    Adding this repository will mean that software which has been classified as non-free will be available to install on your system. This software may not be permitted in some jurisdictions. When installing each package from this repository, you should verify that the laws of your country permit you to use it. Again, this software may not include security updates.

  5. Click Close to save your changes and exit.


Sometimes the Ubuntu developers release feature and security updates for applications and packages within the Ubuntu system.

The Update Manager program will list the available updates. You will find it at Applications->System->Update Manager. To download and install available updates click Install Updates. Ubuntu will then download and install the available updates from the Internet.

When Update Manager has finished updating your system, close Update Manager to finish updating your system.

After installing some important updates, it may be necessary to restart your computer.


Please note that Xubuntu does not by default run the update-notifier known from Ubuntu.