Debian is a community-based Linux project, completed entirely by user contributions. Like many other parts of Linux, it was started by a disgruntled university student. Debian provides the base code for many popular Linux distributions, including SimplyMEPIS, the Ubuntu distros from Canonical, and the popular livecd Linux called Knoppix. Debian is also available in its pure form.
Ubuntu is probably the most well-known Debian-based Linux available nowadays because of its substantial corporate backing. Ubuntu uses the GNOME desktop program, which makes it the choice of some users and a nuisance to others. GNOME is known to have a simple user interface that can be bothersome to some users who prefer substantial workstation customization. Businesses and users new to computing often appreciate the simplicity of the GNOME interface.
KUbuntu is a version of Ubuntu that is tailored to work with the KDE desktop manager. For those users who want to start out customizing their desktop experience, KUbuntu is a good choice for Debian-based Linux distros. KDE offers many settings right out of the box and allows substantial workstation configuration in a simple fashion. KDE also offers some rich KDE-specific programs, though most of the best programs for Linux are not GUI-specific and can run on various desktop programs.
XUbuntu is a version of Ubuntu that uses the XFCE desktop environment as the operating system’s front-end. XFCE is referred to be lightweight because it requires less system resources than some of the other desktop programs to run effectively, leading to a better user experience. XFCE uses XFWM, a composite window manager, as its window manager, allowing for a more sophisticated graphical experience.
SimplyMEPIS and Knoppix are LiveCD-based Linux distros that allow you to try Linux out on your non-Linux pc before installing it. You can boot into Linux and go through a setup process to detect your hardware, etc, and load Linux into temporary memory so you can use your computer as if you have Linux installed for the time your computer is running. If you want to revert to your other operating system, simply shut down. You can install SimplyMEPIS and Knoppix, though, if you so desire and they will function much like any other Debian-like Linux distribution.
Debian uses .deb files with its package manager, dpkg. When installing programs from the command line in Debian-based distros, you will use a program called “apt” (for Advanced Packaging Tool). Using this utility, you can install, upgrade, and remove software from your Linux distribution. Apt will be consistent across Debian-like distros.