In this short article I will show you how to find out the version of a package with dpkg and rpm, on the most used Linux Distros.

For Debian, Ubuntu, Linux Mint, PuppyOS, Knoppix:
Syntax: dpkg -s {package_name}
$ dpkg -s vim | grep -i ^version
Version: 2:7.3.154+hg~74503f6ee649-2ubuntu3.1
$ dpkg -s firefox | grep -i ^version
Version: 7.0.1+build1+nobinonly-0ubuntu2
For Fedora, CentOS, openSUSE, Mandriva:
Syntax: rpm -q {package_name}
$ rpm -q firefox
firefox-7.0.1-1.fc16.x86_64
$ rpm -q gedit
gedit-3.2.1-1.fc16.x86_64
I have tested this commands in Linux Mint and Fedora.
You can find other related articles here.