The Basics

This section covers some basic concepts, and includes information on how to install and change window managers. It follows on from the introduction so you may like to read that first if you haven't already.

Virtual Desktops and Workspaces

As computers are used for such a variety of purposes it makes sense not to have all the windows of all currently running applications on the screen at once, as this can soon get awkward and confusing. Virtually all windowing systems allow you to iconify windows, which shrinks them down to a small icon, ready for when you need the application again. But some window managers also provide the ability to separate windows and tasks in other ways.

The first approach uses the concept of a virtual desktop. This is like having lots of different screens, but all of them can be displayed on your single monitor. These screens can be used to spread out your windows, to prevent clutter. You can move around this grid of screens in various ways, depending on the window manager, and how it is set up. Window managers often provide a pager as well, which is a small diagram of all the screens of the virtual desktop, containing representions of the windows currently open.

Similar to virtual desktops is the concept of workspaces. This involves having multiple, distinct screens, where the intention is for you to group all related windows on one screen, called a workspace. For example you may have a workspace for handling e-mail, one for news, one for word processing, and so on. The window manager often provides a group of buttons, one for each workspace, which are used to select the current workspace.

Changing Window Manager

Obviously if you want to try different window managers you need to know how to change the default window manager. You can't just run it from the command line, as it will complain that there is already a window manager running. However, how you change the window manager is dependent on how your system is set up, and the particular implementation and version of X you are using. The most common scenarios are covered below.

Running X from the command line, using "startx" or "xinit"

The xinit command is the one which actually starts the X Window System, but it usually needs certain options, which is where the startx command comes in. It is simply a shell script which sets up variables, performs any other tasks specific to the local system, and then calls xinit. Therefore you should use startx in preference to xinit if it is available.

There is a system configuration file that startx uses, and a user's own configuration file that is used in preference to the system one, if it exists. You can find out the names of these files by looking at the startx script. (You can find out where the script is by doing "which startx".) The system configuration file is usually something like /etc/X11/xinit/xinitrc and the user configuration file is virtually always .xinitrc in the root of your home directory. Look at the system file and see where it calls the default window manager. To change window managers for yourself, either copy this file to ~/.xinitrc and edit it appropriately, or create your own from scratch. It should end with "exec windowmanager" and any commands before that which don't finish quickly should be run in the background. Here's a simple example: 

     #!/bin/sh
     xterm &
     exec fvwm

The first line selects the program used to run the script itself. Without this your default shell will be used. The second line runs an xterm in the background, and the third line runs the window manager. The exec command is used to replace the script process with the process of the window manager itself. This is because X shuts down when the script finishes running, but if the window manager replaces it, it will shut down when the window manager quits instead, which is usually the desired behaviour.

You can see this for yourself if you change the first line to "exec xterm". The window manager will then not be started and X will shut down when you exit the xterm window. This is also an interesting experience is it illustrates exactly what a window manager does, and what X does itself. Without a window manager running you can still run programs, and bring up windows, but they don't have any decorations and you can't move them.

Running X from a graphical login box, such as with XDM

XDM is the X Display Manager. It starts X when the machine boots up, and then provides a graphical login box instead of the command line, so that when users come and go they don't have to keep starting and quitting X. To configure the setup in this case is similar to that of above, but the user file is now ~/.xsession and the system file something like /etc/X11/xdm/Xsession.

Caution: if you're using startx as above and something goes wrong with the invocation of the window manager you will drop back to the command line and can fix it from here, but if you're using XDM and the same happens, you'll drop back to the login box, without having the chance to fix it. So if you are editing your ~/.xsession file, particularly if you're trying a new window manager for the first time, make sure that either you're logged in elsewhere, and can edit the ~/.xsession file from there, or you use the "exec xterm" approach above, and start the window manager from within the xterm, and only change the ~/.xsession file when you're sure it works okay.

Running X from the CDE graphical login

If you log in with this you will get the CDE (Common Desktop Environment), which uses the DTWM window manager. If you don't want this you can select "Command line login" from the options menu. You should then be able to follow the first scenario above.

Alternatively, you can use the "wmStartupCommand" resource to use a different window manager inside the CDE itself. For example to use fvwm you can have the following in your ~/.Xdefaults file: 

     *wmStartupCommand: /usr/X11R6/bin/fvwm
     *waitWmTimeout: 2
Then when fvwm exits it should call: 
     /usr/dt/bin/dtaction ExitSession
to tell CDE to end the session. For more info see the FVWM FAQ.

Installing a Window Manager

First of all, you don't need to be root to install a new window manager. All you need is enough disk space for the source distribution with room to unpack and then compile it. You may also need some libraries, such as XPM, if they are not already on your system.

Here are the main steps involved:

  1. Download and unpack the distribution. (Tip: if the file is called wm.tar.gz, you can unpack this in one go with "gzcat wm.tar.gz | tar -tf -". If you haven't got gzcat, try "gzip -cd" instead).
  2. If you've been able to find a binary for your platform, then you're sorted. Simply copy it and any other required files to wherever you want them, (or where the instructions tell you to put them), and then change from the default window manage to it, as detailed above.
  3. No binary, so we're going to have to compile the window manager ourselves. First you need to generate a makefile for your platform. This is usually done with either "xmkmf; make Makefiles" or "./configure", but read the instructions for the precise steps required. Most packages come with both a README and an INSTALL file, and are there solely for your benefit.
  4. To actually perform the compilation process, the "make" command is usually run. This calls the compiler for each source code file, and then calls the linker to create an executable. Most window managers consist of many thousands of lines of code, so this can take a while. This is also the step most likely to go wrong. It could fail to find some include files or libraries, which to may need to refer to explicitly in the Imakefile, or sometimes a config.h file. Or the window manager may not have been tested on your platform, and could need detailed knowledge of the platform to get working. If you get completely stuck you could see if anyone on the comp.windows.x newsgroup can help.
  5. Assuming the compilation process does actually complete successfully, you then need to install the window manager and any associated files. You could copy the files to suitable locations yourself if you can see which ones are required. If you do have root access, "make install" will usually do it for you, although it is a good idea to do "make -n install" first, which will show you the steps it would take, without actually performing them. If you don't have root access, you'll need to change the directories used to ones in your home directory if you want to perform this step. This can usually be done in the Imakefile or config.h, but again read the instructions for the particular window manager in question.

That's it. Good luck!