Recently I have been pondering the always recurrent problem of desktop environments and window managers. What with the advent of Gnome 3 and Unity the old ways of using panels and the like appear to be fading into the past. I love the freedom that Linux provides, and that anyone capable of programming it can create a new desktop environment according to what they think will work. I actually quite like both Gnome 3 and Unity, and have experienced none of the instability that others have with them. Still, I find them slow to use and far more reliant on a good computer than necessary. And so, while this has been done countless times before I shall try to detail several ways to get back the older style desktop and hopefully use less resources than those more elaborate setups.
LXDE: LXDE is a light environment with the traditional layout. It does not have that much customizability, but it is perfect if you just want a simple, easy to use and complete environment. LXDE uses the Openbox window manager, so any themes for Openbox will work in LXDE. Many pieces of LXDE will also work in other environments, and are available in individual packages. LXPanel is a very useful panel as it contains an automatically updating menu. LXAppearance can manage GTK themes, icon themes, fonts and, with a plugin, Openbox themes. PCManFm is a light file manager although I prefer Thunar. Leafpad is a light text editor, and LXTerminal is a good terminal.
Xfce: Xfce is a more complete replacement for Gnome 2.X, although it is still missing some features. There are some nice xfwm themes, but Metacity themes often look better. Xfce 4.8 can now use Alacarte to edit it’s menus and, with the help of xfapplet, can use many Gnome applets such as Dockbarx and MintMenu. Xfwm contains it’s own compositor, making Xfce great for those who want to use Docky or AWN without Compiz. Xfce is admittedly not as light as it once was, but it is still lighter than Gnome 2 and is a suitable replacement.
Openbox/Fluxbox/PekWM/Blackbox/Sawfish: All of these window managers are usable alone, some more than others. However, with the addition of a few programs they can be used as a much lighter alternative to a full desktop environment. Setting the wallpaper can be done with Feh or Nitrogen depending on whether you want to have a GUI switcher (Nitrogen) or not. Older versions of PCManFm can manage both the desktop icons and the wallpaper, or you could set up Idesk or ROX Filer (also a great light file manager) to handle the icons. A panel without a menu can be gotten using BMpanel2, Tint2 or Pypanel if one wants to use the right click menu (although Sawfish does not provide one) or with Perlpanel, Qtpanel, Xfce4-panel or Lxpanel if you want a menu. Conky is a very themeable information display that draws to the desktop. Gmrun provides a run dialog, or one could use Demu (be certain to assign dmenu_run to a keyboard shortcut), which provides a different approach at a menu. Stalone tray is a standalone systray for those who don’t want a full panel. In order to build a full environment out of all of this just research what programs you want, download them and add them to a startup file for whatever window manager you are using. Then just log in to the chosen wm.
Icewm/JWM: Icewm and JWM both provide panels with a systray, a clock, a pager, a window list and a menu. IceWM is also capable of managing the wallpaper and is compatible with several (outdated) control panels written specifically for it. They are also both themeable and have editable menus, although one needs to use text files to do it.
Other options: KDE 3 and 4 both use the single panel layout, although I have never really liked either of them and thus know next to nothing about them. It should be fairly simple though. Enlightenment (E17) is nearly a full desktop environment, although it’s a little unconventional, it’s also a great and improving project. Gnome 2 can also still be used, although it is now unmaintained and there will be no more updates. One final option is to use Gnome Shell Frippery, which is a set of extensions for Gnome 3 that adds features such as an applications menu, a window list, a pager, and shifting the clock to the right side of the top panel. All of this makes it look essentially like Gnome 2. The overlay that appears when you move the mouse to the top left of screen is still there, however.
That just about wraps up what I have to say about Linux desktops at this time. Hope that I’ve been helpful, enjoy!