List of installed packages in Ubuntu 8.10

The list of installed packages in Ubunu/ debian can be see by the following command

# dpkg -l

I you want the list of packages along with the disk space they occupy use this variation.

# dpkg-query -W --showformat='${Installed-Size} ${Package}\n' | sort -nr | less

This can be very useful if you install lot of packages and later decide to remove some of them to recover space.