anchor.diff:          services = {
   	  xserver = {
   	    enable = true;
  -            driSupport = true;
  +
  +            displayManager = {
  +	      slim = {
  +	        enable = false;
  +	      };
  +              kdm = {
  +	        enable = true;
  +		extraConfig =
  +                  ''
  +                    [X-:0-Core]
  +                    AutoLoginEnable=true
  +                    AutoLoginUser=alice
  +                    AutoLoginPass=foobar
  +                  '';
  +	      };
  +	    };
  +	    desktopManager = {
  +	      default = "kde4";
  +	      kde4 = {
  +	        enable = true;
  +	      };
  +	    };            
   	  };
   	};
  -	  
  +	
  +	users = {
  +	  extraUsers = pkgs.lib.singleton { 
  +	      name = "alice";
  +              description = "Alice Foobar";
  +              home = "/home/alice";
  +              createHome = true;
  +              useDefaultShell = true;
  +              password = "foobar";
  +          };
  +        };
  + 
           environment = {
   	  extraPackages = [
  -	    pkgs.firefox
  -	    pkgs.icewm
  +	    pkgs.firefoxWrapper
   	    pkgs.scrot
   	  ];
   	};
  
positive.code:       
        $storage->mustSucceed("mkdir -p /repos/trac");
        $storage->mustSucceed("svnadmin create /repos/trac");
        $webserver->mustSucceed("mount storage:/repos/trac /repos/trac");
        
        #$postgresql->waitForFile("/tmp/.s.PGSQL.5432");
        #$postgresql->mustSucceed("createdb trac");
        
        $webserver->waitForFile("/var/trac");
        $webserver->mustSucceed("PYTHONPATH=${pkgs.pythonPackages.psycopg2}/lib/python2.5/site-packages trac-admin /var/trac/projects/test initenv Test postgres://root\@postgresql/trac svn /repos/trac -v");
        
        sleep 10;
        
        $client->waitForFile("/tmp/.X11-unix/X0");
        print STDERR $client->execute("DISPLAY=:0.0 icewm &");
        print STDERR $client->execute("DISPLAY=:0.0 firefox http://webserver/projects/test &");
        
        sleep 40;
        
        print STDERR $client->execute("DISPLAY=:0.0 scrot /hostfs/$ENV{out}/screen1.png");
      '';
  
negative.code:       {config, pkgs, ...}:
        {
          services = {
  	  portmap = {
  	    enable = true;
  	  };
  
            nfsKernel = {
              enable = true;
            };	  
    
            httpd = {
              enable = true;
  