Software packages and programs are freely available for download at multiple online sites with standardized structures, called repositories. There are repositories officially sanctioned and monitored by the Kubuntu/Ubuntu developer community, while other repositories are independently provided, without official sanction or supervision.
Types of Repositories
There are four major package repository types in Ubuntu:
- main - Supported by Canonical. This is the major part of the distribution.
- restricted - Software not licensed under the GPL (or similar software license), but supported by Canonical.
- universe - Software licensed under the GPL (or similar license) and supported by users.
- multiverse - Software not licensed under the GPL (or similar license), but supported by users.
- Karmic-updates - Updates to official packages.
- Karmic-backports - Current version software from Jaunty+1 (Karmic) that have been backported to Jaunty Jackalope.
- Karmic-proposed - Proposed updates & changes (bleeding edge stuff).
Third party repositories
Software developers often maintain their own repositories, from which software packages can be downloaded and installed directly to your computer (if you add the repository to your list). Many of these third party repositories and software packages have never been reviewed by the (K)Ubuntu/Debian community and can present a security risk to your computer. Trojans, backdoors, and other malicious software can be present at any unregulated repository. When using repositories not endorsed by the (K)ubuntu/Debian community, make sure you have utter confidence in that site before enabling the repository and installing a software package from it.
Add Repositories using Synaptic Package Manager
This is the preferred method.
- 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-src http://archive.ubuntu.com/ubuntu/ karmic main restricted
Example: To add the Medibuntu repository, Add:
deb http://packages.medibuntu.org/ karmic 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:
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
