Uninstall / Remove Any Installed Software

GUI Package Management Tool

synaptic is graphical management tool of software packages. It allows you to perform all actions of the command line tool apt-get in a graphical environment. This includes installing, upgrading, downgrading and removing of single packages or even upgrading your whole system.

Just click on System > Administration > Synaptic Package Manager

Now you can select any package and click on Mark for Removal popup meni. You can also start GUI tool from command line, enter:
$ synaptic &

Command Line Package Management Tool

apt-get is the command-line tool for handling packages. It is used for adding / removing / updating packages.

Uninstall / Delete / Remove Package

Just use the following syntax:
sudo apt-get remove {package-name}

For example remove package called mplayer, enter:
$ sudo apt-get remove mplayer

Remove package called lighttpd along with all configuration files, enter:
$ sudo apt-get --purge remove lighttpd

To list all installed package, enter:\
dpkg --list
dpkg --list | less
dpkg --list | grep -i 'http'