Mathias no longer works for Örebro University. These pages are kept for archive purposes only.

Some general linux tips and tricks!

How to use the X11 Xorg composite extension to get translucens windows:

  1. Download the latest release of (, it has to be atleast release X11R6.8.0 (grab the latest cvs snapshot if you down want to use one of the stable releases).
  2. Configure it (see the file BUILD after unpacking it) and enable the composite extension in your newly created config/cf/host.def and add:
    #define BuildComposite          YES
    at the of it.
  3. Build and install everything.
  4. When you start your new X server append the command line option "+extension Composite" to it. Eg use:
    startx -- +extension Composite
  5. Next, we have to get the xcompmgr program running which manager for rendering Composite images out of your normal X windows. The effect of this program is what is actually causing the transluceny effect on your screen. First, see if you can find xcompmgr manually. Otherwise you'll have to grab from CVS as a part of the xapps module.
    cvs -d login
    press return when prompted for a password
    cvs -d co xapps
  6. Configure and install xcompmgr. To do this your might need to do: export PKG_CONFIG_PATH=${PKG_CONFIG_PATH}:/usr/X11R6/lib/pkgconfig
  7. All done... use xcompmgr to do cool things now =)

How to easily  convert arbitrary LaTeX expressions into images for inclusion in for instance webpages, presentations etc.

  1. If you don't already have it, install ImageMagic so that you get the "convert" program.
  2. Download my ftex-to-png script.
  3. Run the script and pipe an arbitrary LaTeX expression into it. Eg:
    BASH> ftex-to-png -
    $$f(x,y,z) = \sqrt{x^2 + y^2 + z^2 - r^2}$$
  4. Copy the resulting image (output.png) to whereever you want it.

Last modified 03/13/12