A Desktop Environment (DE) typically provides a GUI: windows, icons, folders, toolbars, and abilities like dragging and dropping of files from one folder to another. Any DE will therefore include a window manager, file manager, taskbar, and more.
GNOME
The GNU Network Object Model Environment, or GNOME, is an international open source effort to build the simplest and most intuitive GUI for a DE. It’s one of the few DEs that have consistently matched their production timelines, releasing a new version every six months. Currently, it stands at version 2.18. This version focuses on document security, and incorporates privacy features that enable you to digitally sign or authenticate files using Seahorse, an application created for the purpose. That apart, this version also focuses on managing laptop batteries efficiently, and increases the stability and responsiveness of the OS.
GNOME’s popularity in the open source world is due to its exhaustive set of developer guidelines-known as Human Interface Guidelines-to be followed when creating an application for the environment. The guidelines ensure applications don’t look too different from each other, and that some basic options like closing, minimising, and re-sizing, among others, are placed in the same location across all applications.
GNOME’s design keeps novices in mind. The DE does not have a lot customisation options, and contains menus with an exhaustive set of explanation notes. The main reason most Windows-converts should stick to this DE is because it provides a well-documented FAQ section, and a very active online community that will answer any newbie’s questions.
KDE believes in the manifesto that all components used to build the DE, and the applications that come bundled with it, have to be free and open source in the truest sense of the word, with no restrictions whatsoever on the user.
The major difference from GNOME lies in the fact that KDE is not entirely geared towards the novice. It allows for complete customisation, which might intimidate; having said that, there are a good set of applications that allow you to start using a KDE-based distro as soon as you install it. Applications like KOffice, Amarok, and Konqueror are some of the more popular KDE applications. KDE allows you to mimic OSes such as Mac OS X, so if you’re the type who likes to have complete control over each and every aspect of his OS, this is the platform you might want to use.
The most popular distributions on this platform include Fedora (formerly Fedora Core)-though it’s not the default environment-and Knoppix.
The Xfce environment in all its splendour
Popular distros that use Xfce as their default DE include Xubuntu, SLAX, and dyne:bolic.
There are other DEs not as popular as the three above, but worth a mention: