Well-known Linux distributions are Suse, Debian, Red Hat, Ubuntu, and Mandriva. Linux is widely used primarily as an operating system for servers and mainframes, but also in numerous mobile devices such as the Android operating system developed by Google. Linux is mostly used on supercomputers or on the server-side. However, since the last decade, private use in home computers, laptops, video games, cell phones, and other devices has been growing. Although the main use of Linux is through the command line, end-users often use Linux in GUI which makes it appear similar to Windows. Since Linux is open-source, anyone can help develop and improve it. This makes Linux stable and cheap. It also makes it very safe: as soon as you discover a problem you can report it online and often the issue gets resolved within hours.