Skype is proprietary software that allows you to make calls over the Internet using your computer. Skype uses decentralized peer-to-peer technologies, so your calls do not go through a central server, but through distributed servers and other users. It uses its own proprietary communication protocol to achieve this. In addition, all communications are encrypted from end to end so that others cannot listen in. The Skype software is free to use, but it is not free software; the source code is proprietary and not available for modification.
Skype is not available in any Ubuntu software repository, and therefore cannot be installed with Ubuntu's package management software such as Synaptic or apt-get without adding a repository containing Skype. There are two options - the Skype repository, or the Medibuntu repository.
1. Medibuntu Repository
Medibuntu (Multimedia, Entertainment & Distractions In Ubuntu)
is a repository of packages that cannot be included into the Ubuntu
distribution for legal reasons (copyright, license, patent, etc).
have to add medibuntu repository in order to have skype installed. I
am using Ubuntu 7.10 Gutsy with amd64 machine. Other Ubuntu
distribution can use the list from here.
k4tz@k4tz-desktop:~$ sudo wget http://www.medibuntu.org/sources.list.d/gutsy.list -O /etc/apt/sources.list.d/medibuntu.list
k4tz@k4tz-desktop:~$ sudo apt-get update && sudo apt-get install medibuntu-keyring && sudo apt-get update
k4tz@k4tz-desktop:~$ sudo wget -q http://packages.medibuntu.org/medibuntu-key.gpg -O- | sudo apt-key add - && sudo apt-get update
k4tz@k4tz-desktop:~$ sudo apt-get install skype
or in menu :
Applications --- Internet --- Skype
2. Skype Repository
Add this line into /etc/apt/sources.list :
sudo vi /etc/apt/sources.list
deb http://download.skype.com/linux/repos/debian/ stable non-free
sudo apt-get update
sudo apt-get install skype
Note : If we have some problems when installing or using skype for example : sound problem or video problem, we can visit this site.