Desktop environments and window managers

As I wrote in previous post, now I'm going to write about desktop environments (DEs) and window managers (WMs).
When you install a linux distribution, it usually comes with some DE or WM by default. Some distros offer you to choose between several DEs, either that you download different image (later burnt on a CD/DVD or copied to a USB flash drive) from which you install chosen distribution, or during the installation (if image contains all those DEs). If that is not the case, then you can install any of these DEs or WMs from repository or source found on their websites.

Wait! What is DE and what is WM?

The WM stands for the window manager and it is system that controls geometry of your windows on a desktop. In other words, when you open a program, it manages position and size of it, showing you its decoration (border and that thing on the top with maximise, minimise, close, info, etc. buttons) and allowing you to move and resize it.
There is not just one WM and they are of different types:

Floating or stacking: Openbox, IceWM, Twm, Fluxbox, Enlightment, etc.
What are they all about? The windows are rendered one-by-one and one window can overlap the other. That's the most used window manager type.

Tiling: Awesome, dwm, Ion, etc.
In this type you windows don't overlap one another, but they're all placed in tiles. However, sizes and position of the tiles can be changed.

Compositing: Metacity (part of GNOME2), Mutter (part of GNOME3), KWin (part of KDE), Xfwm (part of XFCE), Compiz, etc.
They are usually part of DE. First the window is rendered, and then it image is composed on the screen. With that, you can than apply various visual effects on windows (transparency, shadow, wobbly windows, cube, etc.).

Virtual: Fvwm, Fwvm-crystal, vtwm, etc.
They are actually floating window managers that are using virtual screens, so windows can go out of the screen.


The DE stands for the desktop environment. That is more complex thing than WM, because it contains not only WM, but usually also file manager, display manager, terminal emulator, default programs, libraries, themes, configuration tools, default daemons lunched at start.
Some of the most popular DEs are GNOME, KDE, Xfce, LXDE, Razor-qt, MATE and Cinnamon.

GNOME used to be light DE, but as the years went by GNOME2 is no longer officially developed and we're introduced the GNOME3 (aka GNOME Shell), whis is not light at all.
Default window manager for GNOME2 is Metacity, for GNOME3 it is Mutter. Default file manager is Nautilus, display manager is GDM, and terminal emulator is Gnome-terminal. It is written in GTK+ (C).

KDE is also not very light DE. It's default window manager is KWin and file manager Dolphin. It is written in Qt (C++) and comes with KDM display manager and Konsole as a terminal emulator.

Xfce is, say, light DE, although it also becomes higher and higher. It is now what GNOME2 used to be few years ago.
Xfce is, as GNOME, written in GTK+ (C) and, unlike GNOME, comes with LightDM and has Thunar as default file manager and Xfce4-terminal as terminal emulator.

LXDE really is light DE, but is somehow poorly maintained. It was written in GTK+, but it is migrating to Qt. Its default WM is Openbox, display manager is LXDM, terminal emulator is LXterminal, and file manager is PCManFM.

Razor-qt is lightweight Qt desktop environment.

MATE and Cinnamon are actually a GNOME2 and GNOME3 (respectively) forges used by Linux Mint distribution.