Detecting Underlying Linux Distro

So, you find yourself on a foreign Linux system, but you’ve no idea which distro it is. Here’s a handy little guide.
If you are the owner of the system, then you know which Linux is installed and running. This article will help you to understand how to determine which Linux distribution is installed. You can incorporate this into your application to detect Linux distro.
NOVELL: Cool Solutions: Detecting Underlying Linux Distro