Ubuntu is an extremely popular OS, which makes use of the Linux kernel. Although it's used mainly on desktops, its server version has been rising in popularity lately as well. Ubuntu is one of the lightest Linux distributions you can get and it supports almost any hardware, that makes it a universal OS. It is also very stable and secure and has an a minimum of a five-year support life cycle, so you're able to receive official security and performance updates. Unlike various other OS's, Ubuntu is distributed with no license fees and you can modify its core, as well as any of the countless packages it comes with, in any way you see fit. This enables you to install the right software environment for all your web apps irrespective of their requirements. Due to the popularity of the OS, Ubuntu has large developer and user communities, so you will always find a lot of materials online about any question or problem which you might have.