Bad font anti-aliasing in Ubuntu

There is an old trick to make fonts smoother on Ubuntu (and pretty much every distro running Gnome):

Open up .fonts.conf under your home directory (~/.fonts.conf) and paste this in:

<?xml version="1.0" ?>
<!DOCTYPE fontconfig SYSTEM "fonts.dtd">
   <fontconfig>
      <match target="font">
         <edit name="autohint" mode="assign">
            <bool>true</bool>
         </edit>
      </match>
</fontconfig>

Before:

After:

As John said it, the ~/.fonts.conf file is useful to tweak your font configuration.

I eventually figured out how it works after reading this article :

http://www.kilobitspersecond.com/2009/04/17/ubuntu-font-hinting-you-a-cautionary-tale/