Package sources

Every package comes from a source.

The following are the major types of sources:

• Main
• Restricted
• Universe
• Multiverse
• Partner
• PPAs

The difference between Main, Universe, Restricted and Multiverse can be visualized as:

	Free software	Non-free software
Supported	Main	Restricted
Unsupported	Universe	Multiverse

The list of all above packages can be found at: http://packages.ubuntu.com/. Searchable from: http://packages.ubuntu.com/name

In addition, there are also the partner sources.

On new installs, Main and Restricted sources are enabled by default.

By default, only Main sources are enabled. Enable everything with:

sudo add-apt-repository "deb http://archive.ubuntu.com/ubuntu $(lsb_release -sc) main universe restricted multiverse"
sudo add-apt-repository "deb http://archive.canonical.com/ubuntu $(lsb_release -sc) partner"

Universe

PPAs vs Universe: universe passes some selection form Canonical, PPAs don't.

Pre-installed

List of pre-installed packages perversion: http://askubuntu.com/questions/50077/how-to-get-a-list-of-preinstalled-packages

12.04.4 at http://releases.ubuntu.com/precise/ubuntu-12.04.4-desktop-i386.manifest. Remember that i386 is the 32 bit and amd64 the 64 bit architectures, both used by both Intel and AMD processors.

For other versions see the parent URL.

Main

Officially supported software. Full list for 12.04 + their recommendations + the files they provide: http://packages.ubuntu.com/precise/allpackages. Not possible to see the file contents.

Not all of those packages come pre-installed, they can be installed directly with apt-get since their source is already enabled by default.

Partner

Support is not given by Canonical, but by the company who produces the software.

Notable examples: Flash, Skype.

http://askubuntu.com/questions/456345/what-is-the-difference-between-multiverse-and-partner-sources

Enable:

sudo add-apt-repository "deb http://archive.canonical.com/ubuntu $(lsb_release -sc) partner"