The Ubuntu operating system can be expanded by installing packages from additional repositories, like the Universe, Multiverse and Restricted repositories. Installing these will allow you to install additional applications. Find out how to do this and more.
Additional Repositories in Ubuntu
Ubuntu, the popular Linux operating system, comes by default with it’s own Main repository. If you install simple packages, which normally form part of the Linux operating system, or are closely related to it, it is somewhat likely that it will be present in the Main Ubuntu repository. If they are, it also means that they are officially created (and to some extent supported, for example with security patches) by the Ubuntu team.
The Main repository is enabled by default, and packages within it are open-source, which means you can go and checkout the source code for a particular package, and even propose patches to it etc. It is to a certain extent due to the open-source base that the Linux community has thrived, and become so varied in choice, i.e. with a rich variety of applications available, over the years.
There are three other repositories which you can enable, or disable, namely Universe, Multiverse and Restricted. Also note that you can even disable the Main repository if you would like to, though normally there would not be much sense in doing so, as you would miss out on security updates etc.
What is the Universe Repository?
The Universe repository provides a collection of additional software which can be installed on your Ubuntu workstation. This repository provide community maintained open source software, and whilst there is no official support for the packages/applications within it, most of the software in the Ubuntu Software Centre comes from this repository.
To enable this repository, click on Activities at the top left of your Ubuntu Desktop/GUI and type software. After this, click the ‘Software & Updates’ icon, which is a little darker then the Software Updater icon.
Once inside the Software & Updates window, tick the Community-maintained free and open-source software (universe) selection box. As soon as you do, likely an authentication dialog will present itself. Login by typing the password for the UserID you are using (note the active UserID is shown the dialog box) and clicking Authenticate. Then click the Close button at the bottom right of the dialog box.
As a sidenote, if you find that you have insufficient privileges to take this or other software related actions, you may want to read the How to Control sudo Access on Linux article on how to add your user to the sudoers group, though note that this may have other security implications too, especially if you were to enable password-less sudo privileges for your account (though this is not covered in that article).
A new popup will show:
Click ‘Reload’ to continue, and the software repositories caches (i.e. what is available on the repository is stored locally on your computer) will be refreshed.
What is the Multiverse Repository?
The Ubuntu Multiverse repository is contains software packages which may come with copyright or legal issues. In principle, one would have to see, per-package what the applicable license, legal and restrictive issues are, and how they relate to you and your system.
This repository is also community supported. With potentially less-supported and closed-source packages in this repository, the risk for security issues is somewhat larger here. For example, the community would not be able to patch a closed-source package, and there are less people to maintain packages overall.
On a more general note (and this is by no means applicable to all packages in the multiverse repository), when software is restricted by various licenses, it may in certain cases be fine for a user to install a package which could otherwise not be bundled with the operating system. This can also apply to packages in the restricted repository we will discuss below.
For example, packages which cannot form part of the Ubuntu base operating system (or the Main repository) due to conflicting licensing requirements, may be just fine to be installed, by the user, when installed separately from the operating system as a whole. They may simply not be able to be bundled therewith. One such example would be incompatible open-source licenses which, when used, would change (or want to change) the overall license of other packages. Such packages can therefore not be bundled with the main operating system. One can research packages and their licenses to find out if this applies.
Note that may want to avoid using the multiverse repository on servers, and especially so if those server(s) are public on the Internet.
Enabling the Multiverse repository requires identical steps to the ones shown above, though this time the tick is made for Software restricted by copyright or legal issues (multiverse). Remember to reload when you’re done.
What is the Restricted Repository?
The Ubuntu Restricted repository contains proprietary drivers. For example, you may find NVIDIA GPU drivers in here. This repository is officially supported by the Ubuntu team. The software in this repository is build somewhat ‘downstream‘ from the hardware manufacturers/vendor. For example, NVIDIA may release a new driver set for it’s GPU’s, and the team at Ubuntu will integrate these drivers into it’s restricted repository.
Any software’s in this repository will show the text Proprietary in it’s License section when browsing the Ubuntu Software Centre.
Enabling the Ubuntu Restricted repository again requires identical steps to the ones shown above. Simply tick Proprietary drivers for devices (restricted). And as before, remember to reload when done.
Wrapping up
In this article, we looked at adding the Ubuntu Universe, Multiverse and Restricted repositories. We also learned about the differences between the different repositories and provided some tips along the way. Enjoy!
