How do I update Ubuntu Linux softwares.

Using apt-get command line tool

apt-get is the command-line tool for handling packages. You can use following command options:

=> apt-get update : Update is used to resynchronize the package index files from their sources via Internet.

=> apt-get upgrade : Upgrade is used to install the newest versions of all packages currently installed on the system.

=> apt-get install package-name : install is followed by one or more packages desired for installation. If package is already installed it will try to update to latest version.

=> To upgrade individual software called foo type command: apt-get install foo


More info @ https://help.ubuntu.com/11.04/serverguide/package-management.html 


More info @ http://www.guia-ubuntu.org/index.php?title=A%C3%B1adir_repositorios_externos