Menu -> System -> Administration -> Synaptic Package Manager -> Settings ->
Repositories.
Here you can enable the repositories for Ubuntu Software and Third Party Software.
For Third Party Software select Add -> enter the repository's address. It will have a format similar to:
deb http://archive.ubuntu.com/ubuntu/ trusty main restricted deb-src http://archive.ubuntu.com/ubuntu/ trusty main restricted
Example: To add the Medibuntu repository, Add:
deb http://packages.medibuntu.org/ trusty free non-free
Download the repository key to a folder.
Example: The Medibuntu key can be downloaded from
http://packages.medibuntu.org/medibuntu-key.gpg Then add the key from:
Menu -> System -> Administration -> Synaptic Manager -> Settings -> Repositories -> Authentication -> Import Key File...
(Alternatively, you can manually add the key from the command line Terminal.
See Add Repository keys.)
Refresh the package list from the new repository:
Synaptic -> Reload
Manually add repositories
Adding a repository (such as a Launchpad ppa repository) can be accomplished from the command-line interface:
sudo apt-add-repository ppa:user/repository
where ppa:user/repository is an example of the repository you wish to add.
When the repository name has a format similar to the following, enclose the repository name in quotation marks:
sudo apt-add-repository "deb http://repository.example.org trusty stable"
To remove a repository:
sudo apt-add-repository -r ppa:user/repository
Download and add the repository keys to your keyring. See Add repository keys.
Refresh the packages list from the new repositories:
sudo apt-get update
Note: If add-apt-repository is not available on your system, then install it with the package:
sudo apt-get install python-software-properties
Edit the repository sources list
This is an optional, labor intensive method. Do this at your own risk. Modify the default Ubuntu sources.list only if you understand what you're doing. Mixing repositories can break your system. For more information see the Ubuntu Command-line Repository guide (https://help.ubuntu.com/community/Repositories/CommandLine) .
Create a backup of your current list of sources.
sudo cp -i /etc/apt/sources.list /etc/apt/sources.list_backup
Note: sudo - runs the command with root privileges. cp = copy. -i = prompt to overwrite if a file already exists.
Edit the list of sources:
sudo nano /etc/apt/sources.list
or using a graphical editor:
gksudo gedit /etc/apt/sources.list
Note: To use your local mirror you can add "xx." before archive.ubuntu.com, where xx = your country code.
Example: deb http://gb.archive.ubuntu.com/ubuntu precise main restricted universe multiverse indicates a repository for Great Britain (gb).
Here is a sample sources.list. At the end have been added repositories for Medibuntu and Google:
#deb cdrom:[Ubuntu 14.04 _Trusty Tahr_ - Release i386]/ Trusty main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty main restricted deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty-updates main restricted deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty universe deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty universe deb http://gb.archive.ubuntu.com/ubuntu/ trusty-updates universe deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty multiverse deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty multiverse deb http://gb.archive.ubuntu.com/ubuntu/ trusty-updates multiverse deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-updates multiverse
## Uncomment the following two lines to add software from the 'backports'
## repository.
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://gb.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse deb-src http://gb.archive.ubuntu.com/ubuntu/ trusty-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository. This software is not part of Ubuntu, but is
## offered by Canonical and the respective vendors as a service to Ubuntu
## users.
deb http://archive.canonical.com/ubuntu trusty partner deb-src http://archive.canonical.com/ubuntu trusty partner
deb http://security.ubuntu.com/ubuntu trusty-security main restricted deb-src http://security.ubuntu.com/ubuntu trusty-security main restricted deb http://security.ubuntu.com/ubuntu trusty-security universe
deb-src http://security.ubuntu.com/ubuntu trusty-security universe deb http://security.ubuntu.com/ubuntu trusty-security multiverse deb-src http://security.ubuntu.com/ubuntu trusty-security multiverse
## Medibuntu - Ubuntu 14.04 "Trusty Tahr"
## Please report any bug on https://bugs.launchpad.net/medibuntu/
deb http://packages.medibuntu.org/ trusty free non-free deb-src http://packages.medibuntu.org/ trusty free non-free
# Google software repository
deb http://dl.google.com/linux/deb/ stable non-free
Download and add the repository keys to your keyring. See Add repository keys.
Refresh the packages list from the new repositories:
sudo apt-get update