Ubuntu is a really popular OS, which employs the Linux kernel. Even though it is used primarily on desktops, its server version has been becoming more popular these days as well. Ubuntu is among the lightest Linux releases you can get and it's compatible with almost any kind of hardware, that makes it a universal OS. In addition, it is very stable and secure and has an no less than a 5-year support life cycle, so you will be able to get official security and performance updates. Unlike many other OS's, Ubuntu is distributed devoid of license fees and you are able to customize its core, and / or any of the numerous packages it contains, in any way you find fit. This will allow you to install the optimal software environment for all of your web applications regardless of their requirements. Because of the popularity of the OS, Ubuntu has huge developer and user communities, so you can always find find plenty of materials online related to any question or problem that you might have.